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A ship is a large
watercraft Any vehicle used in or on water as well as underwater, including boats, ships, hovercraft and submarines, is a watercraft, also known as a water vessel or waterborne vessel. A watercraft usually has a propulsive capability (whether by sail, ...
that travels the world's oceans and other sufficiently deep
waterways A waterway is any navigable body of water. Broad distinctions are useful to avoid ambiguity, and disambiguation will be of varying importance depending on the nuance of the equivalent word in other languages. A first distinction is necessary ...
, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished from
boat A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size, shape, cargo or passenger capacity, or its ability to carry boats. Small boats are typically found on inl ...
s, based on size, shape, load capacity, and purpose. Ships have supported
exploration Exploration refers to the historical practice of discovering remote lands. It is studied by geographers and historians. Two major eras of exploration occurred in human history: one of convergence, and one of divergence. The first, covering most ...
,
trade Trade involves the transfer of goods and services from one person or entity to another, often in exchange for money. Economists refer to a system or network that allows trade as a market. An early form of trade, barter, saw the direct excha ...
,
warfare War is an intense armed conflict between states, governments, societies, or paramilitary groups such as mercenaries, insurgents, and militias. It is generally characterized by extreme violence, destruction, and mortality, using regul ...
,
migration Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...
, colonization, and
science Science is a systematic endeavor that Scientific method, builds and organizes knowledge in the form of Testability, testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earli ...
. After the 15th century, new crops that had come from and to the Americas via the European seafarers significantly contributed to
world population growth Population growth is the increase in the number of people in a population or dispersed group. Actual global human population growth amounts to around 83 million annually, or 1.1% per year. The global population has grown from 1 billion in 1800 to ...
.
Ship transport Maritime transport (or ocean transport) and hydraulic effluvial transport, or more generally waterborne transport, is the transport of people ( passengers) or goods (cargo) via waterways. Freight transport by sea has been widely used throu ...
is responsible for the largest portion of world commerce. The word ''ship'' has meant, depending on the era and the context, either just a large vessel or specifically a
ship-rigged A full-rigged ship or fully rigged ship is a sailing vessel's sail plan with three or more masts, all of them square-rigged. A full-rigged ship is said to have a ship rig or be ship-rigged. Such vessels also have each mast stepped in three s ...
sailing ship A sailing ship is a sea-going vessel that uses sails mounted on masts to harness the power of wind and propel the vessel. There is a variety of sail plans that propel sailing ships, employing square-rigged or fore-and-aft sails. Some ships ...
with three or more masts, each of which is
square-rigged Square rig is a generic type of sail and rigging arrangement in which the primary driving sails are carried on horizontal spars which are perpendicular, or square, to the keel of the vessel and to the masts. These spars are called ''yards'' and ...
. As of 2016, there were more than 49,000
merchant ship A merchant ship, merchant vessel, trading vessel, or merchantman is a watercraft that transports cargo or carries passengers for hire. This is in contrast to pleasure craft, which are used for personal recreation, and naval ships, which are ...
s, totaling almost 1.8 billion dead weight tons. Of these 28% were
oil tanker An oil tanker, also known as a petroleum tanker, is a ship designed for the bulk transport of oil or its products. There are two basic types of oil tankers: crude tankers and product tankers. Crude tankers move large quantities of unrefined cru ...
s, 43% were
bulk carrier A bulk carrier or bulker is a merchant ship specially designed to transport unpackaged bulk cargo — such as grains, coal, ore, steel coils, and cement — in its cargo holds. Since the first specialized bulk carrier was built in 1852, eco ...
s, and 13% were
container ship A container ship (also called boxship or spelled containership) is a cargo ship that carries all of its load in truck-size intermodal containers, in a technique called containerization. Container ships are a common means of commercial intermoda ...
s.


Nomenclature

Ships are typically larger than boats, but there is no universally accepted distinction between the two. Ships generally can remain at sea for longer periods of time than boats. A legal definition of ship from
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
n case law is a vessel that carries goods by sea. A common notion is that a ship can carry a boat, but not ''vice versa''. A ship is likely to have a full-time crew assigned. A US Navy rule of thumb is that ships heel towards the ''outside'' of a sharp turn, whereas boats heel towards the ''inside'' because of the relative location of the center of mass versus the center of buoyancy. American and British 19th century maritime law distinguished "vessels" from other watercraft; ships and boats fall in one legal category, whereas open boats and rafts are not considered vessels. Particularly in the Age of Sail, the word ''ship'' might apply generally to a seagoing vessel or particularly to a full-rigged sailing ship with three or more masts, all square-rigged. Other rigs on seagoing vessels included brig,
barque A barque, barc, or bark is a type of sailing vessel with three or more masts having the fore- and mainmasts rigged square and only the mizzen (the aftmost mast) rigged fore and aft. Sometimes, the mizzen is only partly fore-and-aft rigged, b ...
, and
barquentine A barquentine or schooner barque (alternatively "barkentine" or "schooner bark") is a sailing vessel with three or more masts; with a square rigged foremast and fore-and-aft rigged main, mizzen and any other masts. Modern barquentine sailing ...
. Some large vessels are traditionally called ''boats'', notably submarines. Others include
Great Lakes freighters Great may refer to: Descriptions or measurements * Great, a relative measurement in physical space, see Size * Greatness, being divine, majestic, superior, majestic, or transcendent People * List of people known as "the Great" *Artel Great (born ...
,
riverboat A riverboat is a watercraft designed for inland navigation on lakes, rivers, and artificial waterways. They are generally equipped and outfitted as work boats in one of the carrying trades, for freight or people transport, including luxury un ...
s, and
ferryboat A ferry is a ship, watercraft or amphibious vehicle used to carry passengers, and sometimes vehicles and cargo, across a body of water. A passenger ferry with many stops, such as in Venice, Italy, is sometimes called a water bus or water tax ...
s, which may be designed for operation on inland or protected coastal waters. In most maritime traditions ships have individual names, and modern ships may belong to a
ship class A ship class is a group of ships of a similar design. This is distinct from a ship type, which might reflect a similarity of tonnage or intended use. For example, is a nuclear aircraft carrier (ship type) of the (ship class). In the course ...
often named after its first ship. In many documents the ship name is introduced with a ship prefix being an abbreviation of the ship class, for example "MS" (motor ship) or "SV" (sailing vessel), making it easier to distinguish a ship name from other individual names in a text. "Ship" (along with "nation") is an English word that has retained a female
grammatical gender In linguistics, grammatical gender system is a specific form of noun class system, where nouns are assigned with gender categories that are often not related to their real-world qualities. In languages with grammatical gender, most or all noun ...
in some usages, which allows it sometimes to be referred to as a "she" without being of female
natural gender In linguistics, grammatical gender system is a specific form of noun class system, where nouns are assigned with gender categories that are often not related to their real-world qualities. In languages with grammatical gender, most or all nouns ...
.


History


Prehistory and antiquity


Asian developments

The earliest attestations of ships in
maritime transport Maritime transport (or ocean transport) and hydraulic effluvial transport, or more generally waterborne transport, is the transport of people ( passengers) or goods (cargo) via waterways. Freight transport by sea has been widely used throu ...
in
Mesopotamia Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the ...
are
model ship Ship models or model ships are scale models of ships. They can range in size from 1/6000 scale wargaming miniatures to large vessels capable of holding people. Ship modeling is a craft as old as shipbuilding itself, stretching back to ancient t ...
s, which date back to the 4th millennium BC. In archaic texts in
Uruk Uruk, also known as Warka or Warkah, was an ancient city of Sumer (and later of Babylonia) situated east of the present bed of the Euphrates River on the dried-up ancient channel of the Euphrates east of modern Samawah, Al-Muthannā, Iraq.Harm ...
, Sumer, the ideogram for "ship" is attested, but in the inscriptions of the kings of
Lagash Lagash (cuneiform: LAGAŠKI; Sumerian: ''Lagaš''), was an ancient city state located northwest of the junction of the Euphrates and Tigris rivers and east of Uruk, about east of the modern town of Ash Shatrah, Iraq. Lagash (modern Al-Hiba) w ...
, ships were first mentioned in connection to
maritime trade Maritime may refer to: Geography * Maritime Alps, a mountain range in the southwestern part of the Alps * Maritime Region, a region in Togo * Maritime Southeast Asia * The Maritimes, the Canadian provinces of Nova Scotia, New Brunswick, and Princ ...
and naval warfare at around 2500–2350 BCE.
Austronesian peoples The Austronesian peoples, sometimes referred to as Austronesian-speaking peoples, are a large group of peoples in Taiwan, Maritime Southeast Asia, Micronesia, coastal New Guinea, Island Melanesia, Polynesia, and Madagascar that speak Austro ...
originated in what is now
Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...
. From here, they took part in the
Austronesian Expansion The Austronesian peoples, sometimes referred to as Austronesian-speaking peoples, are a large group of peoples in Taiwan, Maritime Southeast Asia, Micronesia, coastal New Guinea, Island Melanesia, Polynesia, and Madagascar that speak Austron ...
. Their distinctive maritime technology was integral to this movement and included catamarans and
outriggers An outrigger is a projecting structure on a boat, with specific meaning depending on types of vessel. Outriggers may also refer to legs on a wheeled vehicle that are folded out when it needs stabilization, for example on a crane that lifts ...
. It has been deduced that they had sails some time before 2000 BCE. Their
crab claw sail The crab claw sail is a fore-and-aft triangular sail with spars along upper and lower edges. The crab claw sail was first developed by the Austronesian peoples some time around 1500 BC. It is used in many traditional Austronesian cultures in Islan ...
s enabled them to sail for vast distances in open ocean. From Taiwan, they rapidly colonized the islands of
Maritime Southeast Asia Maritime Southeast Asia comprises the countries of Brunei, Indonesia, Malaysia, the Philippines, Singapore, and East Timor. Maritime Southeast Asia is sometimes also referred to as Island Southeast Asia, Insular Southeast Asia or Oceanic Sout ...
, then sailed further onwards to
Micronesia Micronesia (, ) is a subregion of Oceania, consisting of about 2,000 small islands in the western Pacific Ocean. It has a close shared cultural history with three other island regions: the Philippines to the west, Polynesia to the east, and ...
,
Island Melanesia Island Melanesia is a subregion of Melanesia in Oceania. It is located east of New Guinea island, from the Bismarck Archipelago to New Caledonia.Steadman, 2006. ''Extinction & biogeography of tropical Pacific birds'' See also Archaeology an ...
,
Polynesia Polynesia () "many" and νῆσος () "island"), to, Polinisia; mi, Porinihia; haw, Polenekia; fj, Polinisia; sm, Polenisia; rar, Porinetia; ty, Pōrīnetia; tvl, Polenisia; tkl, Polenihia (, ) is a subregion of Oceania, made up of ...
, and
Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
, eventually colonizing a territory spanning half the globe. Austronesian rigs were distinctive in that they had spars supporting both the upper and lower edges of the sails (and sometimes in between). The sails were also made from woven leaves, usually from pandan plants. These were complemented by paddlers, who usually positioned themselves on platforms on the
outrigger An outrigger is a projecting structure on a boat, with specific meaning depending on types of vessel. Outriggers may also refer to legs on a wheeled vehicle that are folded out when it needs stabilization, for example on a crane that lifts ...
s in the larger boats. Austronesian ships ranged in complexity from simple
dugout canoe A dugout canoe or simply dugout is a boat made from a hollowed tree. Other names for this type of boat are logboat and monoxylon. ''Monoxylon'' (''μονόξυλον'') (pl: ''monoxyla'') is Greek – ''mono-'' (single) + '' ξύλον xylon'' ( ...
s with outriggers or lashed together to large edge-pegged plank-built boats built around a keel made from a dugout canoe. Their designs were unique, evolving from ancient rafts to the characteristic double-hulled, single-outrigger, and double-outrigger designs of Austronesian ships. Early Austronesian sailors influenced the development of sailing technologies in Sri Lanka and
Southern India South India, also known as Dakshina Bharata or Peninsular India, consists of the peninsular southern part of India. It encompasses the Indian states of Andhra Pradesh, Karnataka, Kerala, Tamil Nadu, and Telangana, as well as the union territ ...
through the Austronesian maritime trade network of the
Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...
, the precursor to the spice trade route and the
maritime silk road The Maritime Silk Road or Maritime Silk Route is the Maritime history, maritime section of the historic Silk Road that connected Southeast Asia, China, the Indian subcontinent, the Arabian peninsula, Somalia, Egypt and Europe. It began by the 2n ...
, which was established at around 1500 BC. Some scholars believe that the triangular Austronesian crab claw sail may have influenced the development of the
lateen A lateen (from French ''latine'', meaning "Latin") or latin-rig is a triangular sail set on a long yard mounted at an angle on the mast, and running in a fore-and-aft direction. The settee can be considered to be an associated type of the same ...
sail in western ships due to early contact. The junk rigs of Chinese ships is also believed to be developed from tilted sails.Needham, Joseph (1971). ''Science and Civilisation in China: Volume 4, Physics and Physical Technology, Part III: Civil Engineering and Nautics''. Cambridge: Cambridge University Press. In the 2nd century AD, people from the
Indonesian archipelago The islands of Indonesia, also known as the Indonesian Archipelago ( id, Kepulauan Indonesia) or Nusantara, may refer either to the islands comprising the country of Indonesia or to the geographical groups which include its islands. History ...
already made large ships measuring over 50 m long and standing 4–7 m out of the water. They could carry 600–1000 people and 250–1000 ton cargo. These ships were known as ''kunlun bo'' or '' k'unlun po'' (崑崙舶, lit. "ship of the
Kunlun The Kunlun Mountains ( zh, s=昆仑山, t=崑崙山, p=Kūnlún Shān, ; ug, كۇئېنلۇن تاغ تىزمىسى / قۇرۇم تاغ تىزمىسى ) constitute one of the longest mountain chains in Asia, extending for more than . In the bro ...
people") by the Chinese, and ''kolandiaphonta'' by the Greeks. They had 4–7 masts and were able to sail against the wind due to the usage of
tanja sail Tanja sail ( Malay: ''layar tanjak'') or tanja rig is a type of sail commonly used by the Austronesian people, particularly in Maritime Southeast Asia. It is also known as the tilted square sail, canted rectangular sail, rectangular balance lug, ...
s. These ships may have reached as far as
Ghana Ghana (; tw, Gaana, ee, Gana), officially the Republic of Ghana, is a country in West Africa. It abuts the Gulf of Guinea and the Atlantic Ocean to the south, sharing borders with Ivory Coast in the west, Burkina Faso in the north, and To ...
. In the 11th century, a new type of ship called djong or jong was recorded in Java and Bali. This type of ship was built using wooden dowels and treenails, unlike the ''kunlun bo'' which used vegetal fibres for lashings. In China, miniature models of ships that feature steering oars have been dated to the
Warring States period The Warring States period () was an era in ancient Chinese history characterized by warfare, as well as bureaucratic and military reforms and consolidation. It followed the Spring and Autumn period and concluded with the Qin wars of conquest ...
(c. 475–221 BC). By the
Han dynasty The Han dynasty (, ; ) was an imperial dynasty of China (202 BC – 9 AD, 25–220 AD), established by Liu Bang (Emperor Gao) and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–207 BC) and a warr ...
, a well kept naval fleet was an integral part of the military. Sternpost-mounted rudders started to appear on Chinese ship models starting in the 1st century AD. However, these early Chinese ships were fluvial (riverine), and were not seaworthy. The Chinese only acquired sea-going ship technologies in the 10th century AD
Song Dynasty The Song dynasty (; ; 960–1279) was an imperial dynasty of China that began in 960 and lasted until 1279. The dynasty was founded by Emperor Taizu of Song following his usurpation of the throne of the Later Zhou. The Song conquered the rest ...
after contact with Southeast Asian ''k'un-lun po'' trading ships, leading to the development of the junks.


Mediterranean developments

Archaeological evidence in
Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medit ...
, dated to 3000 BC, shows wooden planks assembled into a hull. They used woven straps to lash the planks together, and reeds or grass stuffed between the planks helped to seal the seams. The
Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...
historian A historian is a person who studies and writes about the past and is regarded as an authority on it. Historians are concerned with the continuous, methodical narrative and research of past events as relating to the human race; as well as the st ...
and
geographer A geographer is a physical scientist, social scientist or humanist whose area of study is geography, the study of Earth's natural environment and human society, including how society and nature interacts. The Greek prefix "geo" means "earth" a ...
Agatharchides Agatharchides or Agatharchus ( grc-gre, Ἀγαθαρχίδης or , ''Agatharchos'') of Cnidus was a Greek historian and geographer (flourished 2nd century BC). Life Agatharchides is believed to have been born at Cnidus, hence his appellation. A ...
had documented ship-faring among the early Egyptians: ''"During the prosperous period of the
Old Kingdom In ancient Egyptian history, the Old Kingdom is the period spanning c. 2700–2200 BC. It is also known as the "Age of the Pyramids" or the "Age of the Pyramid Builders", as it encompasses the reigns of the great pyramid-builders of the Fourth ...
, between the 30th and 25th centuries BC, the
river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of w ...
-routes were kept in order, and
Egyptian Egyptian describes something of, from, or related to Egypt. Egyptian or Egyptians may refer to: Nations and ethnic groups * Egyptians, a national group in North Africa ** Egyptian culture, a complex and stable culture with thousands of years of ...
ships sailed the
Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; ...
as far as the myrrh-country."''
Sneferu Sneferu ( snfr-wj "He has perfected me", from ''Ḥr-nb-mꜣꜥt-snfr-wj'' "Horus, Lord of Maat, has perfected me", also read Snefru or Snofru), well known under his Hellenized name Soris ( grc-koi, Σῶρις by Manetho), was the founding phar ...
's ancient cedar wood ship Praise of the Two Lands is the first reference recorded (2613 BC) to a ship being referred to by name. The ancient Egyptians were perfectly at ease building sailboats. A remarkable example of their
shipbuilding Shipbuilding is the construction of ships and other floating vessels. It normally takes place in a specialized facility known as a shipyard. Shipbuilders, also called shipwrights, follow a specialized occupation that traces its roots to befo ...
skills was the
Khufu ship The Khufu ship is an intact full-size solar barque from ancient Egypt. It was sealed into a pit at the foot of the Great Pyramid of pharaoh Khufu around 2500 BC, during the Fourth Dynasty of the ancient Egyptian Old Kingdom. Like other buried ...
, a vessel in length entombed at the foot of the
Great Pyramid of Giza The Great Pyramid of Giza is the biggest Egyptian pyramid and the tomb of Fourth Dynasty pharaoh Khufu. Built in the early 26th century BC during a period of around 27 years, the pyramid is the oldest of the Seven Wonders of the Ancient Worl ...
around 2500 BC and found intact in 1954. The oldest discovered sea faring hulled boat is the
Late Bronze Age The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second prin ...
Uluburun The Uluburun Shipwreck is a Late Bronze Age shipwreck dated to the late 14th century BC, discovered close to the east shore of Uluburun (Grand Cape), Turkey, in the Mediterranean Sea. The shipwreck was discovered in the summer of 1982 by Mehmed Ç ...
shipwreck off the coast of Turkey, dating back to 1300 BC. By 1200 B.C., the
Phoenicia Phoenicia () was an ancient thalassocratic civilization originating in the Levant region of the eastern Mediterranean, primarily located in modern Lebanon. The territory of the Phoenician city-states extended and shrank throughout their histor ...
ns were building large merchant ships. In world maritime history, declares Richard Woodman, they are recognized as "the first true seafarers, founding the art of pilotage,
cabotage Cabotage () is the transport of goods or passengers between two places in the same country. It originally applied to shipping along coastal routes, port to port, but now applies to aviation, railways, and road transport as well. Cabotage rights ar ...
, and navigation" and the architects of "the first true ship, built of planks, capable of carrying a deadweight cargo and being sailed and steered."


14th through the 18th centuries


Asian developments

At this time, ships were developing in Asia in much the same way as Europe. Japan used defensive naval techniques in the
Mongol invasions of Japan Major military efforts were taken by Kublai Khan of the Yuan dynasty in 1274 and 1281 to conquer the Japanese archipelago after the submission of the Korean kingdom of Goryeo to vassaldom. Ultimately a failure, the invasion attempts are of m ...
in 1281. It is likely that the Mongols of the time took advantage of both European and Asian shipbuilding techniques. During the 15th century, China's
Ming dynasty The Ming dynasty (), officially the Great Ming, was an imperial dynasty of China, ruling from 1368 to 1644 following the collapse of the Mongol-led Yuan dynasty. The Ming dynasty was the last orthodox dynasty of China ruled by the Han peo ...
assembled one of the largest and most powerful naval fleets in the world for the diplomatic and power projection voyages of
Zheng He Zheng He (; 1371–1433 or 1435) was a Chinese mariner, explorer, diplomat, fleet admiral, and court eunuch during China's early Ming dynasty. He was originally born as Ma He in a Muslim family and later adopted the surname Zheng conferr ...
. Elsewhere in Japan in the 15th century, one of the world's first iron-clads, "Tekkōsen" ( 鉄甲船), literally meaning "iron ships", was also developed. In Japan, during the Sengoku era from the 15th century to 17th century, the great struggle for feudal supremacy was fought, in part, by coastal fleets of several hundred boats, including the
atakebune or were large Japanese warships of the 16th and 17th century used during the internecine Japanese wars for political control and unity of all Japan. History Japan undertook major naval building efforts in the mid to late 16th century, during t ...
. In Korea, in the early 15th century during the Joseon era, " Geobukseon"(거북선), was developed. The empire of Majapahit used large ships called jong, built in northern Java, for transporting troops overseas. The jongs were transport ships which could carry 100–2000 tons of cargo and 50–1000 people, 28.99–88.56 meter in length. The exact number of jong fielded by Majapahit is unknown, but the largest number of jong deployed in an expedition is about 400 jongs, when Majapahit attacked Pasai, in 1350.Hill (June 1960). " Hikayat Raja-Raja Pasai". ''Journal of the Malaysian Branch of the Royal Asiatic Society''. 33: p. 98 and 157: "Then he directed them to make ready all the equipment and munitions of war needed for an attack on the land of Pasai – about four hundred of the largest junks, and also many barges (malangbang) and galleys." See also Nugroho (2011). p. 270 and 286, quoting ''Hikayat Raja-Raja Pasai'', 3: 98: "''Sa-telah itu, maka di-suroh baginda musta'idkan segala kelengkapan dan segala alat senjata peperangan akan mendatangi negeri Pasai itu, sa-kira-kira empat ratus jong yang besar-besar dan lain daripada itu banyak lagi daripada malangbang dan kelulus''." (After that, he is tasked by His Majesty to ready all the equipment and all weapons of war to come to that country of Pasai, about four hundred large jongs and other than that much more of malangbang and kelulus.)


European developments

Several civilizations became sea powers. Such examples include the maritime republics of
Genoa Genoa ( ; it, Genova ; lij, Zêna ). is the capital of the Italian region of Liguria and the sixth-largest city in Italy. In 2015, 594,733 people lived within the city's administrative limits. As of the 2011 Italian census, the Province of ...
and
Venice Venice ( ; it, Venezia ; vec, Venesia or ) is a city in northeastern Italy and the capital of the Veneto region. It is built on a group of 118 small islands that are separated by canals and linked by over 400 bridges. The isla ...
, Hanseatic League, and the Byzantine navy. The
Viking Vikings ; non, víkingr is the modern name given to seafaring people originally from Scandinavia (present-day Denmark, Norway and Sweden), who from the late 8th to the late 11th centuries raided, pirated, traded and se ...
s used their
knarr A knarr is a type of Norse merchant ship used by the Vikings. The knarr ( non, knǫrr, plural ) was constructed using the same clinker-built method as longships, karves, and faerings. History ''Knarr'' is the Old Norse term for a type of ...
s to explore North America, trade in the
Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and ...
and plunder many of the coastal regions of Western Europe. Towards the end of the 14th century, ships like the carrack began to develop towers on the bow and stern. These towers decreased the vessel's stability, and in the 15th century, the
caravel The caravel (Portuguese: , ) is a small maneuverable sailing ship used in the 15th century by the Portuguese to explore along the West African coast and into the Atlantic Ocean. The lateen sails gave it speed and the capacity for sailing win ...
, designed by the
Portuguese Portuguese may refer to: * anything of, from, or related to the country and nation of Portugal ** Portuguese cuisine, traditional foods ** Portuguese language, a Romance language *** Portuguese dialects, variants of the Portuguese language ** Portu ...
, based on the Arabic ''qarib'' which could sail closer to the wind, became more widely used. The towers were gradually replaced by the
forecastle The forecastle ( ; contracted as fo'c'sle or fo'c's'le) is the upper deck of a sailing ship forward of the foremast, or, historically, the forward part of a ship with the sailors' living quarters. Related to the latter meaning is the phrase " be ...
and sterncastle, as in the carrack ''Santa María'' of
Christopher Columbus Christopher Columbus * lij, Cristoffa C(or)ombo * es, link=no, Cristóbal Colón * pt, Cristóvão Colombo * ca, Cristòfor (or ) * la, Christophorus Columbus. (; born between 25 August and 31 October 1451, died 20 May 1506) was a ...
. This increased
freeboard In sailing and boating, a vessel's freeboard is the distance from the waterline to the upper deck level, measured at the lowest point of sheer where water can enter the boat or ship. In commercial vessels, the latter criterion measured relativ ...
allowed another innovation: the freeing port, and the artillery associated with it. The carrack and then the
caravel The caravel (Portuguese: , ) is a small maneuverable sailing ship used in the 15th century by the Portuguese to explore along the West African coast and into the Atlantic Ocean. The lateen sails gave it speed and the capacity for sailing win ...
were developed in
Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...
. After Columbus, European exploration rapidly accelerated, and many new trade routes were established. In 1498, by reaching India, Vasco da Gama proved that access to the
Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...
from the
Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
was possible. These explorations in the Atlantic and Indian Oceans were soon followed by
France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
,
England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...
and the
Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...
, who explored the Portuguese and Spanish trade routes into the
Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...
, reaching Australia in 1606 and
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
in 1642.


Specialization and modernization

Parallel to the development of warships, ships in service of marine fishery and trade also developed in the period between antiquity and the Renaissance. Maritime trade was driven by the development of shipping companies with significant financial resources. Canal barges, towed by draft animals on an adjacent
towpath A towpath is a road or trail on the bank of a river, canal, or other inland waterway. The purpose of a towpath is to allow a land vehicle, beasts of burden, or a team of human pullers to tow a boat, often a barge. This mode of transport w ...
, contended with the
railway Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...
up to and past the early days of the
industrial revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
. Flat-bottomed and flexible
scow A scow is a smaller type of barge. Some scows are rigged as sailing scows. In the 19th and early 20th centuries, scows carried cargo in coastal waters and inland waterways, having an advantage for navigating shallow water or small harbours. S ...
boats also became widely used for transporting small cargoes. Mercantile trade went hand-in-hand with exploration, self-financed by the commercial benefits of exploration. During the first half of the 18th century, the
French Navy The French Navy (french: Marine nationale, lit=National Navy), informally , is the maritime arm of the French Armed Forces and one of the five military service branches of France. It is among the largest and most powerful naval forces in t ...
began to develop a new type of vessel known as a ship of the line, featuring seventy-four guns. This type of ship became the backbone of all European fighting fleets. These ships were long and their construction required 2,800 oak trees and of rope; they carried a crew of about 800 sailors and soldiers. During the 19th century the
Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against ...
enforced a ban on the
slave trade Slavery and enslavement are both the state and the condition of being a slave—someone forbidden to quit one's service for an enslaver, and who is treated by the enslaver as property. Slavery typically involves slaves being made to perf ...
, acted to suppress
piracy Piracy is an act of robbery or criminal violence by ship or boat-borne attackers upon another ship or a coastal area, typically with the goal of stealing cargo and other valuable goods. Those who conduct acts of piracy are called pirates, v ...
, and continued to map the world. A clipper was a very fast sailing ship of the 19th century. The
clipper route The clipper route was the traditional route derived from the Brouwer Route and sailed by clipper ships between Europe and the Far East, Australia and New Zealand. The route ran from west to east through the Southern Ocean, to make use of the s ...
s fell into commercial disuse with the introduction of steam ships with better fuel efficiency, and the opening of the
Suez Suez ( ar, السويس '; ) is a seaport city (population of about 750,000 ) in north-eastern Egypt, located on the north coast of the Gulf of Suez (a branch of the Red Sea), near the southern terminus of the Suez Canal, having the same bou ...
and
Panama Canal The Panama Canal ( es, Canal de Panamá, link=no) is an artificial waterway in Panama that connects the Atlantic Ocean with the Pacific Ocean and divides North and South America. The canal cuts across the Isthmus of Panama and is a condui ...
s. Ship designs stayed fairly unchanged until the late 19th century. The industrial revolution, new mechanical methods of
propulsion Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived f ...
, and the ability to construct ships from metal triggered an explosion in ship design. Factors including the quest for more efficient ships, the end of long running and wasteful maritime conflicts, and the increased financial capacity of industrial powers created an avalanche of more specialized boats and ships. Ships built for entirely new functions, such as firefighting, rescue, and research, also began to appear.


21st century

In 2019, the world's fleet included 51,684 commercial vessels with gross tonnage of more than 1,000 tons, totaling 1.96 billion tons. Such ships carried 11 billion tons of cargo in 2018, a sum that grew by 2.7% over the previous year. In terms of tonnage, 29% of ships were
tankers Tanker may refer to: Transportation * Tanker, a tank crewman (US) * Tanker (ship), a ship designed to carry bulk liquids ** Chemical tanker, a type of tanker designed to transport chemicals in bulk ** Oil tanker, also known as a petroleum tank ...
, 43% are
bulk carrier A bulk carrier or bulker is a merchant ship specially designed to transport unpackaged bulk cargo — such as grains, coal, ore, steel coils, and cement — in its cargo holds. Since the first specialized bulk carrier was built in 1852, eco ...
s, 13%
container ship A container ship (also called boxship or spelled containership) is a cargo ship that carries all of its load in truck-size intermodal containers, in a technique called containerization. Container ships are a common means of commercial intermoda ...
s and 15% were other types. In 2008, there were 1,240
warship A warship or combatant ship is a naval ship that is built and primarily intended for naval warfare. Usually they belong to the armed forces of a state. As well as being armed, warships are designed to withstand damage and are usually faster ...
s operating in the world, not counting small vessels such as
patrol boat A patrol boat (also referred to as a patrol craft, patrol ship, or patrol vessel) is a relatively small naval vessel generally designed for coastal defence, border security, or law enforcement. There are many designs for patrol boats, and the ...
s. The
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
accounted for 3 million tons worth of these vessels,
Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
1.35 million tons, the
United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
504,660 tons and China 402,830 tons. The 20th century saw many naval engagements during the two
world war A world war is an international conflict which involves all or most of the world's major powers. Conventionally, the term is reserved for two major international conflicts that occurred during the first half of the 20th century, World WarI (1914 ...
s, the Cold War, and the rise to power of naval forces of the two blocs. The world's major powers have recently used their naval power in cases such as the
United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
in the
Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouze ...
and the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
in
Iraq Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to the north, Iran to the east, the Persian Gulf and K ...
. The size of the world's
fishing fleet A fishing fleet is an aggregate of commercial fishing vessels. The term may be used of all vessels operating out of a particular port, all vessels engaged in a particular type of fishing (as in the "tuna fishing fleet"), or all fishing vessels of ...
is more difficult to estimate. The largest of these are counted as commercial vessels, but the smallest are legion.
Fishing vessel A fishing vessel is a boat or ship used to catch fish in the sea, or on a lake or river. Many different kinds of vessels are used in commercial, artisanal and recreational fishing. The total number of fishing vessels in the world in 2016 was ...
s can be found in most seaside villages in the world. As of 2004, the United Nations
Food and Agriculture Organization The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...
estimated 4 million fishing vessels were operating worldwide. The same study estimated that the world's 29 million fishermen caught of fish and shellfish that year.


Types of ships

Because ships are constructed using the principles of naval architecture that require same structural components, their classification is based on their function such as that suggested by Paulet and Presles, which requires modification of the components. The categories accepted in general by naval architects are: *
High-speed craft A high-speed craft (HSC) is a high-speed water vessel for civilian use, also called a fastcraft or fast ferry. The first high-speed craft were often hydrofoils or hovercraft, but in the 1990s catamaran and monohull designs become more po ...
Multihulls including wave piercers,
small-waterplane-area twin hull A small waterplane area twin hull, better known by the acronym SWATH, is a catamaran design that minimizes hull cross section area at the sea's surface. Minimizing the ship's volume near the surface area of the sea, where wave energy is located ...
(SWATH),
surface effect ship A Surface Effect Ship (SES) or Sidewall Hovercraft is a watercraft that has both an air cushion, like a hovercraft, and twin hulls, like a catamaran. When the air cushion is in use, a small portion of the twin hulls remains in the water. When the ...
s and hovercraft, hydrofoil, wing in ground effect craft (WIG). * Off shore oil vessels –
Platform supply vessel A platform supply vessel (PSV) is a ship specially designed to supply offshore oil and gas platforms. These ships range from in length and accomplish a variety of tasks. The primary function for most of these vessels is logistic support and tr ...
, pipe layers, accommodation and crane
barge Barge nowadays generally refers to a flat-bottomed inland waterway vessel which does not have its own means of mechanical propulsion. The first modern barges were pulled by tugs, but nowadays most are pushed by pusher boats, or other vessels ...
s, non and semi-submersible
drilling rig A drilling rig is an integrated system that drills wells, such as oil or water wells, or holes for piling and other construction purposes, into the earth's subsurface. Drilling rigs can be massive structures housing equipment used to drill wa ...
s, production platforms, floating production storage and offloading units. *
Fishing vessel A fishing vessel is a boat or ship used to catch fish in the sea, or on a lake or river. Many different kinds of vessels are used in commercial, artisanal and recreational fishing. The total number of fishing vessels in the world in 2016 was ...
s ** Motorised
fishing trawler A fishing trawler is a commercial fishing vessel designed to operate fishing trawls. Trawling is a method of fishing that involves actively dragging or pulling a trawl through the water behind one or more trawlers. Trawls are fishing nets th ...
s, trap setters, seiners, longliners, trollers &
factory ship A factory ship, also known as a fish processing vessel, is a large ocean-going vessel with extensive on-board facilities for processing and freezing caught fish or whales. Modern factory ships are automated and enlarged versions of the earlier wh ...
s. ** Traditional
sailing Sailing employs the wind—acting on sails, wingsails or kites—to propel a craft on the surface of the ''water'' (sailing ship, sailboat, raft, windsurfer, or kitesurfer), on ''ice'' (iceboat) or on ''land'' (land yacht) over a chosen cou ...
and rowed fishing vessels and
boat A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size, shape, cargo or passenger capacity, or its ability to carry boats. Small boats are typically found on inl ...
s used for
handline fishing Handline fishing, or handlining, is a fishing technique where a single fishing line is held in the hands, rather than with a fishing rod like the usual angling. It is a type of angling, and is not to be confused with handfishing, which is catch ...
* Harbour work craft ** Cable layers **
Tugboat A tugboat or tug is a marine vessel that manoeuvres other vessels by pushing or pulling them, with direct contact or a tow line. These boats typically tug ships in circumstances where they cannot or should not move under their own power, su ...
s,
dredger Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing da ...
s, salvage vessels, tenders,
Pilot boat A pilot boat is a type of boat used to transport maritime pilots between land and the inbound or outbound ships that they are piloting. Pilot boats were once sailing boats that had to be fast because the first pilot to reach the incoming ship ...
s. ** Floating dry docks, floating cranes, lightership. * Dry cargo ships – tramp freighters, bulk carriers, cargo liners, container vessels, barge carriers, Ro-Ro ships, refrigerated cargo ships, timber carriers, livestock & light vehicle carriers. * Liquid cargo ships – oil tankers, liquefied gas carriers, chemical carriers. * Passenger vessels ** Liners, cruise and special trade passenger (STP) ships ** Cross-channel, coastal and harbour ferries ** Luxury and cruising yachts ** Sail training and multi-masted ships * Recreational boats and craft – rowed, masted and motorised craft * Special-purpose vessels –
weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloud cover, cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmos ...
and
research vessel A research vessel (RV or R/V) is a ship or boat designed, modified, or equipped to carry out research at sea. Research vessels carry out a number of roles. Some of these roles can be combined into a single vessel but others require a dedicated ...
s, deep sea
survey vessel A survey vessel is any type of ship or boat that is used for underwater surveys, usually to collect data for mapping or planning underwater construction or mineral extraction. It is a type of research vessel, and may be designed for the pur ...
s, and
icebreaker An icebreaker is a special-purpose ship or boat designed to move and navigate through ice-covered waters, and provide safe waterways for other boats and ships. Although the term usually refers to ice-breaking ships, it may also refer to smaller ...
s. * Submersibles – industrial exploration, scientific research, tourist and hydrographic survey. *
Warships A warship or combatant ship is a naval ship that is built and primarily intended for naval warfare. Usually they belong to the armed forces of a state. As well as being armed, warships are designed to withstand damage and are usually faster an ...
and other surface combatantsaircraft carriers, destroyers, frigates, corvettes,
minesweeper A minesweeper is a small warship designed to remove or detonate naval mines. Using various mechanisms intended to counter the threat posed by naval mines, minesweepers keep waterways clear for safe shipping. History The earliest known usage of ...
s, etc. Some of these are discussed in the following sections.


Inland vessels

Freshwater shipping may occur on lakes, rivers and canals. Ships designed for those body of waters may be specially adapted to the widths and depths of specific waterways. Examples of freshwater waterways that are navigable in part by large vessels include the
Danube The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , p ...
,
Mississippi Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...
,
Rhine ), Surselva, Graubünden, Switzerland , source1_coordinates= , source1_elevation = , source2 = Rein Posteriur/Hinterrhein , source2_location = Paradies Glacier, Graubünden, Switzerland , source2_coordinates= , so ...
,
Yangtze The Yangtze or Yangzi ( or ; ) is the longest river in Asia, the third-longest in the world, and the longest in the world to flow entirely within one country. It rises at Jari Hill in the Tanggula Mountains (Tibetan Plateau) and flows ...
and
Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technolog ...
Rivers, and the
Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lak ...
.


Great Lakes

Lake freighter Lake freighters, or lakers, are bulk carrier vessels that operate on the Great Lakes of North America. These vessels are traditionally called boats, although classified as ships. Since the late 19th century, lakers have carried bulk cargoes of ma ...
s, also called lakers, are
cargo Cargo consists of bulk goods conveyed by water, air, or land. In economics, freight is cargo that is transported at a freight rate for commercial gain. ''Cargo'' was originally a shipload but now covers all types of freight, including trans ...
vessels that ply the
Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lak ...
. The most well-known is , the latest major vessel to be wrecked on the Lakes. These vessels are traditionally called boats, not ships. Visiting ocean-going vessels are called "salties". Because of their additional beam, very large salties are never seen inland of the
Saint Lawrence Seaway The St. Lawrence Seaway (french: la Voie Maritime du Saint-Laurent) is a system of locks, canals, and channels in Canada and the United States that permits oceangoing vessels to travel from the Atlantic Ocean to the Great Lakes of North Ameri ...
. Because the smallest of the
Soo Locks The Soo Locks (sometimes spelled Sault Locks but pronounced "soo") are a set of parallel locks, operated and maintained by the United States Army Corps of Engineers, Detroit District, that enable ships to travel between Lake Superior and the low ...
is larger than any Seaway lock, salties that can pass through the Seaway may travel anywhere in the Great Lakes. Because of their deeper draft, salties may accept partial loads on the Great Lakes, "topping off" when they have exited the Seaway. Similarly, the largest lakers are confined to the Upper Lakes ( Superior,
Michigan Michigan () is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the List of U.S. states and ...
,
Huron Huron may refer to: People * Wyandot people (or Wendat), indigenous to North America * Wyandot language, spoken by them * Huron-Wendat Nation, a Huron-Wendat First Nation with a community in Wendake, Quebec * Nottawaseppi Huron Band of Potawatomi ...
,
Erie Erie (; ) is a city on the south shore of Lake Erie and the county seat of Erie County, Pennsylvania, United States. Erie is the fifth largest city in Pennsylvania and the largest city in Northwestern Pennsylvania with a population of 94,831 a ...
) because they are too large to use the Seaway locks, beginning at the
Welland Canal The Welland Canal is a ship canal in Ontario, Canada, connecting Lake Ontario and Lake Erie. It forms a key section of the St. Lawrence Seaway and Great Lakes Waterway. Traversing the Niagara Peninsula from Port Weller in St. Catharines ...
that bypasses the Niagara River. Since the freshwater lakes are less corrosive to ships than the
salt water Saline water (more commonly known as salt water) is water that contains a high concentration of dissolved salts (mainly sodium chloride). On the United States Geological Survey (USGS) salinity scale, saline water is saltier than brackish wat ...
of the oceans, lakers tend to last much longer than ocean freighters. Lakers older than 50 years are not unusual, and as of 2005, all were over 20 years of age. , built in 1906 as ''William P Snyder'', was the oldest laker still working on the Lakes until its conversion into a barge starting in 2013. Similarly, ''E.M. Ford'', built in 1898 as ''Presque Isle'', was sailing the lakes 98 years later in 1996. As of 2007 ''E.M. Ford'' was still afloat as a stationary transfer vessel at a riverside cement silo in
Saginaw, Michigan Saginaw () is a city in the U.S. state of Michigan and the seat of Saginaw County. The city of Saginaw and Saginaw County are both in the area known as Mid-Michigan. Saginaw is adjacent to Saginaw Charter Township and considered part of Greater ...
.


Merchant ship

Merchant ship A merchant ship, merchant vessel, trading vessel, or merchantman is a watercraft that transports cargo or carries passengers for hire. This is in contrast to pleasure craft, which are used for personal recreation, and naval ships, which are ...
s are ships used for commercial purposes and can be divided into four broad categories: fishing, cargo ships, passenger ships, and special-purpose ships. The
UNCTAD review of maritime transport The ''Review of Maritime Transport'' (RMT) an annual publication by the United Nations Conference on Trade and Development (UNCTAD). It provides an analysis of structural and cyclical changes affecting seaborne trade, ports and shipping, as well a ...
categorizes ships as: oil tankers, bulk (and combination) carriers, general cargo ships, container ships, and "other ships", which includes " liquefied petroleum gas carriers,
liquefied natural gas Liquefied natural gas (LNG) is natural gas (predominantly methane, CH4, with some mixture of ethane, C2H6) that has been cooled down to liquid form for ease and safety of non-pressurized storage or transport. It takes up about 1/600th the vol ...
carriers, parcel (chemical) tankers, specialized tankers, reefers, offshore supply, tugs, dredgers, cruise, ferries, other non-cargo". General cargo ships include "multi-purpose and project vessels and roll-on/roll-off cargo". Modern commercial vessels are typically powered by a single propeller driven by a
diesel Diesel may refer to: * Diesel engine, an internal combustion engine where ignition is caused by compression * Diesel fuel, a liquid fuel used in diesel engines * Diesel locomotive, a railway locomotive in which the prime mover is a diesel engin ...
or, less usually,
gas turbine engine A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directi ...
., but until the mid-19th century they were predominantly square sail rigged. The fastest vessels may use pump-jet engines. Most commercial vessels have full hull-forms to maximize cargo capacity. Hulls are usually made of steel, although aluminum can be used on faster craft, and fiberglass on the smallest service vessels. Commercial vessels generally have a crew headed by a sea captain, with
deck officer The deck department is an organisational team on board naval and merchant ships. The department and its manning requirements, including the responsibilities of each rank are regulated within the STCW Convention, applicable only to the merchant ...
s and
engine officer An engineering officer or simply engineer, is a licensed mariner qualified and responsible for operating and maintaining the propulsion plants and support systems for a watercraft and its crew, passengers and cargo.Wise Geek''What is the Engine ...
s on larger vessels. Special-purpose vessels often have specialized crew if necessary, for example scientists aboard
research vessel A research vessel (RV or R/V) is a ship or boat designed, modified, or equipped to carry out research at sea. Research vessels carry out a number of roles. Some of these roles can be combined into a single vessel but others require a dedicated ...
s. Fishing boats are generally small, often little more than but up to for a large tuna or
whaling ship A whaler or whaling ship is a specialized vessel, designed or adapted for whaling: the catching or processing of whales. Terminology The term ''whaler'' is mostly historic. A handful of nations continue with industrial whaling, and one, Jap ...
. Aboard a fish processing vessel, the catch can be made ready for market and sold more quickly once the ship makes port. Special purpose vessels have special gear. For example, trawlers have winches and arms, stern-trawlers have a rear ramp, and tuna seiners have skiffs. In 2004, of fish were caught in the marine capture fishery.UNFAO, 2007, p. 11. Anchoveta represented the largest single catch at . That year, the top ten marine capture species also included
Alaska pollock The Alaska pollock or walleye pollock (''Gadus chalcogrammus'') is a marine fish species of the cod genus '' Gadus'' and family Gadidae. It is a semi-pelagic schooling fish widely distributed in the North Pacific, with largest concentrations ...
,
Blue whiting The blue whiting (''Micromesistius poutassou'') one of the two species in the genus '' Micromesistius'' in the family Gadidae, which also contains cod, haddock, whiting, and pollock. It is common in the northeast Atlantic Ocean from Morocco to ...
, Skipjack tuna, Atlantic herring,
Chub mackerel The chub mackerel, Pacific mackerel, or Pacific chub mackerel (''Scomber japonicus'') is a species of fish in the tuna and mackerel family, Scombridae. This species of mackerel closely resembles the Atlantic chub mackerel. Characteristics The chu ...
, Japanese anchovy,
Chilean jack mackerel The Chilean jack mackerel (''Trachurus murphyi''), sometimes called the Inca scad or Peruvian jack mackerel, is a species of jack mackerel in the genus ''Trachurus'' of the family Carangidae. Since the 1970s, it has become one of the world's mor ...
, Largehead hairtail, and
Yellowfin tuna The yellowfin tuna (''Thunnus albacares'') is a species of tuna found in pelagic waters of tropical and subtropical oceans worldwide. Yellowfin is often marketed as ahi, from the Hawaiian , a name also used there for the closely related bigeye ...
. Other species including
salmon Salmon () is the common name for several commercially important species of euryhaline ray-finned fish from the family Salmonidae, which are native to tributaries of the North Atlantic (genus ''Salmo'') and North Pacific (genus '' Oncorhy ...
, shrimp, lobster,
clam Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that are edible and live as infauna, spending most of their lives halfway buried in the sand of the seafloor or riverbeds. Clams have two shel ...
s, squid and crab, are also commercially fished. Modern commercial fishermen use many methods. One is fishing by nets, such as
purse seine Seine fishing (or seine-haul fishing; ) is a method of fishing that employs a surrounding net, called a seine, that hangs vertically in the water with its bottom edge held down by weights and its top edge buoyed by floats. Seine nets can be de ...
, beach seine, lift nets, gillnets, or entangling nets. Another is
trawl Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different speci ...
ing, including
bottom trawl Bottom trawling is trawling (towing a trawl, which is a fishing net) along the seafloor. It is also referred to as "dragging". The scientific community divides bottom trawling into benthic trawling and demersal trawling. Benthic trawling is tow ...
. Hooks and lines are used in methods like
long-line fishing Longline fishing, or longlining, is a commercial fishing angling technique that uses a long ''main line'' with baited hooks attached at intervals via short branch lines called ''snoods'' or ''gangions''.hand-line fishing. Another method is the use of
fishing trap A fish trap is a trap used for fishing. Fish traps include fishing weirs, lobster traps, and some fishing nets such as fyke nets. Traps are culturally almost universal and seem to have been independently invented many times. There are two mai ...
. Cargo ships transport dry and liquid cargo. Dry cargo can be transported in bulk by
bulk carrier A bulk carrier or bulker is a merchant ship specially designed to transport unpackaged bulk cargo — such as grains, coal, ore, steel coils, and cement — in its cargo holds. Since the first specialized bulk carrier was built in 1852, eco ...
s, packed directly onto a general cargo ship in break-bulk, packed in
intermodal container An intermodal container, often called a shipping container, is a large standardized shipping container, designed and built for intermodal freight transport, meaning these containers can be used across different modes of transport – from ship ...
s as aboard a
container ship A container ship (also called boxship or spelled containership) is a cargo ship that carries all of its load in truck-size intermodal containers, in a technique called containerization. Container ships are a common means of commercial intermoda ...
, or driven aboard as in roll-on roll-off ships. Liquid cargo is generally carried in bulk aboard tankers, such as
oil tanker An oil tanker, also known as a petroleum tanker, is a ship designed for the bulk transport of oil or its products. There are two basic types of oil tankers: crude tankers and product tankers. Crude tankers move large quantities of unrefined cru ...
s which may include both crude and finished products of oil, chemical tankers which may also carry vegetable oils other than chemicals and
gas carrier A gas carrier, gas tanker, LPG carrier, or LPG tanker is a ship designed to transport Liquefied petroleum gas, LPG, LNG, CNG, or liquefied chemical gases in Bulk liquids, bulk. Types Fully pressurized gas carrier The seaborne transport of li ...
s, although smaller shipments may be carried on container ships in
tank container A tank container or tanktainer is an intermodal container for the transport of liquids, gases and powders as bulk cargo. It is built to the ISO standards, making it suitable for different modes of transportation; as such, it is also called an ISO ...
s. Passenger ships range in size from small river ferries to very large
cruise ship Cruise ships are large passenger ships used mainly for vacationing. Unlike ocean liners, which are used for transport, cruise ships typically embark on round-trip voyages to various ports-of-call, where passengers may go on tours known as ...
s. This type of vessel includes
ferries A ferry is a ship, watercraft or amphibious vehicle used to carry passengers, and sometimes vehicles and cargo, across a body of water. A passenger ferry with many stops, such as in Venice, Italy, is sometimes called a water bus or water tax ...
, which move passengers and vehicles on short trips; ocean liners, which carry passengers from one place to another; and
cruise ship Cruise ships are large passenger ships used mainly for vacationing. Unlike ocean liners, which are used for transport, cruise ships typically embark on round-trip voyages to various ports-of-call, where passengers may go on tours known as ...
s, which carry passengers on voyages undertaken for pleasure, visiting several places and with leisure activities on board, often returning them to the port of embarkation.
Riverboat A riverboat is a watercraft designed for inland navigation on lakes, rivers, and artificial waterways. They are generally equipped and outfitted as work boats in one of the carrying trades, for freight or people transport, including luxury un ...
s and inland ferries are specially designed to carry passengers, cargo, or both in the challenging river environment. Rivers present special hazards to vessels. They usually have varying water flows that alternately lead to high speed water flows or protruding rock hazards. Changing siltation patterns may cause the sudden appearance of shoal waters, and often floating or sunken logs and trees (called snags) can endanger the hulls and propulsion of riverboats. Riverboats are generally of shallow draft, being broad of beam and rather square in plan, with a low freeboard and high topsides. Riverboats can survive with this type of configuration as they do not have to withstand the high winds or large waves that are seen on large lakes, seas, or oceans.
Fishing vessel A fishing vessel is a boat or ship used to catch fish in the sea, or on a lake or river. Many different kinds of vessels are used in commercial, artisanal and recreational fishing. The total number of fishing vessels in the world in 2016 was ...
s are a subset of commercial vessels, but generally small in size and often subject to different regulations and classification. They can be categorized by several criteria: architecture, the type of fish they catch, the fishing method used, geographical origin, and technical features such as rigging. As of 2004, the world's fishing fleet consisted of some 4 million vessels.UNFAO, 2007, p. 25. Of these, 1.3 million were decked vessels with enclosed areas and the rest were open vessels. Most decked vessels were mechanized, but two-thirds of the open vessels were traditional craft propelled by sails and oars. More than 60% of all existing large fishing vessels were built in Japan, Peru, the Russian Federation, Spain or the United States of America.


Special purpose vessels

A
weather ship A weather ship, or ocean station vessel, was a ship stationed in the ocean for surface and upper air meteorological observations for use in weather forecasting. They were primarily located in the north Atlantic and north Pacific oceans, reportin ...
was a ship stationed in the
ocean The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the wo ...
as a platform for surface and upper air meteorological observations for use in
marine weather forecasting Marine weather forecasting is the process by which mariners and meteorological organizations attempt to forecast future weather conditions over the Earth's oceans. Mariners have had rules of thumb regarding the navigation around tropical cyclone ...
. Surface weather observations were taken hourly, and four radiosonde releases occurred daily. It was also meant to aid in search and rescue operations and to support transatlantic flights. Proposed as early as 1927 by the
aviation Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air craft such as hot a ...
community, the establishment of weather ships proved to be so useful during
World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
that the
International Civil Aviation Organization The International Civil Aviation Organization (ICAO, ) is a specialized agency of the United Nations that coordinates the principles and techniques of international air navigation, and fosters the planning and development of international a ...
(ICAO) established a global network of weather ships in 1948, with 13 to be supplied by the United States. This number was eventually negotiated down to nine. The weather ship crews were normally at sea for three weeks at a time, returning to port for 10-day stretches. Weather ship observations proved to be helpful in wind and wave studies, as they did not avoid weather systems like other ships tended to for safety reasons. They were also helpful in monitoring storms at sea, such as
tropical cyclone A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depen ...
s. The removal of a weather ship became a negative factor in forecasts leading up to the Great Storm of 1987. Beginning in the 1970s, their role became largely superseded by
weather buoy Weather buoys are instruments which collect weather and ocean data within the world's oceans, as well as aid during emergency response to chemical spills, legal proceedings, and engineering design. Moored buoys have been in use since 1951, wh ...
s due to the ships' significant cost. The agreement of the use of weather ships by the international community ended in 1990. The last weather ship was '' Polarfront'', known as weather station M ("Mike"), which was put out of operation on 1 January 2010. Weather observations from ships continue from a fleet of voluntary merchant vessels in routine commercial operation.


Naval vessels

Naval ship A naval ship is a military ship (or sometimes boat, depending on classification) used by a navy. Naval ships are differentiated from civilian ships by construction and purpose. Generally, naval ships are Damage control, damage resilient a ...
s are diverse in types of vessel. They include: surface warships, submarines, and
auxiliary ship An auxiliary ship is a naval ship designed to support combatant ships and other naval operations. Auxiliary ships are not primary combatant vessels, though they may have some limited combat capacity, usually for purposes of self-defense. Auxil ...
s. Modern warships are generally divided into seven main categories: aircraft carriers, cruisers, destroyers, frigates, corvettes, submarines and
amphibious assault ship An amphibious assault ship is a type of amphibious warfare ship employed to land and support ground forces on enemy territory by an amphibious assault. The design evolved from aircraft carriers converted for use as helicopter carriers (and, a ...
s. The distinctions among cruisers, destroyers, frigates, and corvettes are not codified; the same vessel may be described differently in different navies. Battleships were used during the
Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...
and occasionally since then (the last battleships were removed from the U.S. Naval Vessel Register in March 2006), but were made obsolete by the use of carrier-borne aircraft and guided missiles. Most military submarines are either
attack submarine An attack submarine or hunter-killer submarine is a submarine specifically designed for the purpose of attacking and sinking other submarines, surface combatants and merchant vessels. In the Soviet and Russian navies they were and are called ...
s or ballistic missile submarines. Until the end of
World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
the primary role of the diesel/electric submarine was anti-ship warfare, inserting and removing covert agents and military forces, and intelligence-gathering. With the development of the
homing torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, su ...
, better
sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on o ...
systems, and
nuclear propulsion Nuclear propulsion includes a wide variety of propulsion methods that use some form of nuclear reaction as their primary power source. The idea of using nuclear material for propulsion dates back to the beginning of the 20th century. In 1903 it was ...
, submarines also became able to effectively hunt each other. The development of submarine-launched nuclear and
cruise missiles A cruise missile is a guided missile used against terrestrial or naval targets that remains in the atmosphere and flies the major portion of its flight path at approximately constant speed. Cruise missiles are designed to deliver a large warhe ...
gave submarines a substantial and long-ranged ability to attack both land and sea targets with a variety of weapons ranging from cluster munitions to
nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bom ...
s. Most
navies A navy, naval force, or maritime force is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake-borne, riverine, littoral, or ocean-borne combat operations and related functions. It includ ...
also include many types of support and auxiliary vessel, such as
minesweepers A minesweeper is a small warship designed to remove or detonate naval mines. Using various mechanisms intended to counter the threat posed by naval mines, minesweepers keep waterways clear for safe shipping. History The earliest known usage of ...
,
patrol boat A patrol boat (also referred to as a patrol craft, patrol ship, or patrol vessel) is a relatively small naval vessel generally designed for coastal defence, border security, or law enforcement. There are many designs for patrol boats, and the ...
s,
offshore patrol vessels Offshore may refer to: Science and technology * Offshore (hydrocarbons) * Offshore construction, construction out at sea * Offshore drilling, discovery and development of oil and gas resources which lie underwater through drilling a well * O ...
,
replenishment ship A replenishment oiler or replenishment tanker is a naval auxiliary ship with fuel tanks and dry cargo holds which can supply both fuel and dry stores during underway replenishment (UNREP) at sea. Many countries have used replenishment oilers. Th ...
s, and
hospital ship A hospital ship is a ship designated for primary function as a floating medical treatment facility or hospital. Most are operated by the military forces (mostly navies) of various countries, as they are intended to be used in or near war zones. I ...
s which are designated medical treatment facilities. Fast combat vessels such as cruisers and destroyers usually have fine hulls to maximize speed and maneuverability. They also usually have advanced
marine electronics Marine electronics refers to electronics devices designed and classed for use in the marine environment on board ships and yachts where even a small amount of salt water can destroy some electronics devices. Therefore, the majority of these types of ...
and communication systems, as well as weapons.


Architecture

Some components exist in vessels of any size and purpose. Every vessel has a hull of sorts. Every vessel has some sort of propulsion, whether it's a pole, an ox, or a nuclear reactor. Most vessels have some sort of steering system. Other characteristics are common, but not as universal, such as compartments, holds, a superstructure, and equipment such as anchors and winches.


Hull

For a ship to float, its weight must be less than that of the water displaced by the ship's hull. There are many types of hulls, from logs lashed together to form a raft to the advanced hulls of America's Cup sailboats. A vessel may have a single hull (called a monohull design), two in the case of catamarans, or three in the case of trimarans. Vessels with more than three hulls are rare, but some experiments have been conducted with designs such as pentamarans. Multiple hulls are generally parallel to each other and connected by rigid arms. Hulls have several elements. The bow is the foremost part of the hull. Many ships feature a
bulbous bow A bulbous bow is a protruding bulb at the bow (or front) of a ship just below the waterline. The bulb modifies the way the water flows around the hull, reducing drag and thus increasing speed, range, fuel efficiency, and stability. Large ships w ...
. The
keel The keel is the bottom-most longitudinal structural element on a vessel. On some sailboats, it may have a hydrodynamic and counterbalancing purpose, as well. As the laying down of the keel is the initial step in the construction of a ship, in Br ...
is at the very bottom of the hull, extending the entire length of the ship. The rear part of the hull is known as the stern, and many hulls have a flat back known as a transom. Common hull appendages include propellers for propulsion,
rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adve ...
s for steering, and stabilizers to quell a ship's rolling motion. Other hull features can be related to the vessel's work, such as fishing gear and sonar domes. Hulls are subject to various hydrostatic and hydrodynamic constraints. The key hydrostatic constraint is that it must be able to support the entire weight of the boat, and maintain stability even with often unevenly distributed weight. Hydrodynamic constraints include the ability to withstand shock waves, weather collisions and groundings. Older ships and pleasure craft often have or had wooden hulls. Steel is used for most commercial vessels. Aluminium is frequently used for fast vessels, and
composite material A composite material (also called a composition material or shortened to composite, which is the common name) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or ...
s are often found in sailboats and pleasure craft. Some ships have been made with concrete hulls.


Propulsion systems

Propulsion systems for ships fall into three categories: human propulsion,
sailing Sailing employs the wind—acting on sails, wingsails or kites—to propel a craft on the surface of the ''water'' (sailing ship, sailboat, raft, windsurfer, or kitesurfer), on ''ice'' (iceboat) or on ''land'' (land yacht) over a chosen cou ...
, and mechanical propulsion. Human propulsion includes
rowing Rowing is the act of propelling a human-powered watercraft using the sweeping motions of oars to displace water and generate reactional propulsion. Rowing is functionally similar to paddling, but rowing requires oars to be mechanically ...
, which was used even on large galleys. Propulsion by sail generally consists of a sail hoisted on an erect mast, supported by stays and spars and controlled by ropes. Sail systems were the dominant form of propulsion until the 19th century. They are now generally used for recreation and competition, although experimental sail systems, such as the
turbosail The turbosail or French is a marine propulsion system using a sail-like vertical surface and a powered boundary layer control system to improve lift across a wide angle of attack. This allows the sail to power the boat in any direction simply by ...
s, rotorsails, and
wingsail A wingsail, twin-skin sail or double skin sail is a variable-camber aerodynamic structure that is fitted to a marine vessel in place of conventional sails. Wingsails are analogous to airplane wings, except that they are designed to provide lif ...
s have been used on larger modern vessels for fuel savings. Mechanical propulsion systems generally consist of a motor or engine turning a propeller, or less frequently, an
impeller An impeller or impellor is a rotor used to increase the pressure and flow of a fluid. It is the opposite of a turbine, which extracts energy from, and reduces the pressure of, a flowing fluid. In pumps An impeller is a rotating componen ...
or wave propulsion fins. Steam engines were first used for this purpose, but have mostly been replaced by
two-stroke A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of ...
or four-stroke diesel engines, outboard motors, and
gas turbine engine A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directi ...
s on faster ships. Nuclear reactors producing steam are used to propel
warship A warship or combatant ship is a naval ship that is built and primarily intended for naval warfare. Usually they belong to the armed forces of a state. As well as being armed, warships are designed to withstand damage and are usually faster ...
s and
icebreaker An icebreaker is a special-purpose ship or boat designed to move and navigate through ice-covered waters, and provide safe waterways for other boats and ships. Although the term usually refers to ice-breaking ships, it may also refer to smaller ...
s, and there have been attempts to use them to power commercial vessels (see NS ''Savannah''). In addition to traditional fixed and controllable pitch propellers there are many specialized variations, such as contra-rotating and nozzle-style propellers. Most vessels have a single propeller, but some large vessels may have up to four propellers supplemented with transverse thrusters for maneuvring at ports. The propeller is connected to the main engine via a propeller shaft and, in case of medium- and high-speed engines, a reduction gearbox. Some modern vessels have a diesel-electric powertrain in which the propeller is turned by an
electric motor An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate for ...
powered by the ship's generators.


Steering systems

For ships with independent propulsion systems for each side, such as manual oars or some
paddles A paddle is a handheld tool with an elongated handle and a flat, widened distal end (i.e. the ''blade''), used as a lever to apply force onto the bladed end. It most commonly describes a completely handheld tool used to propel a human-powered w ...
, steering systems may not be necessary. In most designs, such as boats propelled by engines or sails, a steering system becomes necessary. The most common is a rudder, a submerged plane located at the rear of the hull. Rudders are rotated to generate a lateral force which turns the boat. Rudders can be rotated by a
tiller A tiller or till is a lever used to steer a vehicle. The mechanism is primarily used in watercraft, where it is attached to an outboard motor, rudder post or stock to provide leverage in the form of torque for the helmsman to turn the rudder. ...
, manual wheels, or electro-hydraulic systems.
Autopilot An autopilot is a system used to control the path of an aircraft, marine craft or spacecraft without requiring constant manual control by a human operator. Autopilots do not replace human operators. Instead, the autopilot assists the operator' ...
systems combine mechanical rudders with navigation systems.
Ducted propeller A ducted propeller, also known as a Kort nozzle, is a marine propeller fitted with a non-rotating nozzle. It is used to improve the efficiency of the propeller and is especially used on heavily loaded propellers or propellers with limited dia ...
s are sometimes used for steering. Some propulsion systems are inherently steering systems. Examples include the
outboard motor An outboard motor is a propulsion system for boats, consisting of a self-contained unit that includes engine, gearbox and propeller or jet drive, designed to be affixed to the outside of the transom. They are the most common motorised method ...
, the
bow thruster Manoeuvering thruster (bow thruster or stern thruster) is a transversal propulsion device built into, or mounted to, either the bow or stern, of a ship or boat to make it more manoeuvrable. Bow thrusters make docking easier, since they allow th ...
, and the
Z-drive A Z-drive is a type of marine propulsion unit. Specifically, it is an azimuth thruster. The pod can rotate 360 degrees allowing for rapid changes in thrust direction and thus vessel direction. This eliminates the need for a conventional rudder. ...
.


Holds, compartments, and the superstructure

Larger boats and ships generally have multiple decks and compartments. Separate
berthing A cabin or berthing is an enclosed space generally on a ship or an aircraft. A cabin which protrudes above the level of a ship's deck may be referred to as a deckhouse. Sailing ships In sailing ships, the officers and paying passengers wo ...
s and heads are found on sailboats over about . Fishing boats and cargo ships typically have one or more cargo holds. Most larger vessels have an engine room, a galley, and various compartments for work. Tanks are used to store fuel, engine oil, and fresh water. Ballast tanks are equipped to change a ship's trim and modify its stability. Superstructures are found above the main deck. On sailboats, these are usually very low. On modern cargo ships, they are almost always located near the ship's stern. On passenger ships and warships, the superstructure generally extends far forward.


Equipment

Shipboard equipment varies from ship to ship depending on such factors as the ship's era, design, area of operation, and purpose. Some types of equipment that are widely found include: * Masts can be the home of antennas, navigation lights, radar transponders, fog signals, and similar devices often required by law. * Ground tackle comprises the anchor, its chain or cable, and connecting fittings. * Cargo equipment such as cranes and cargo booms may be used to load and unload cargo and ship's stores. * Safety equipment such as
lifeboats Lifeboat may refer to: Rescue vessels * Lifeboat (shipboard), a small craft aboard a ship to allow for emergency escape * Lifeboat (rescue), a boat designed for sea rescues * Airborne lifeboat, an air-dropped boat used to save downed airmen A ...
,
liferaft A lifeboat or liferaft is a small, rigid or inflatable boat carried for emergency evacuation in the event of a disaster aboard a ship. Lifeboat drills are required by law on larger commercial ships. Rafts ( liferafts) are also used. In the m ...
s, and
survival suit A survival suit, more accurately and currently referred to as an immersion suit, is a type of waterproof dry suit intended to protect the wearer from hypothermia if immersed in cold water or otherwise exposed after abandoning a vessel, especial ...
s are carried aboard many vessels for emergency use.


Design considerations


Hydrostatics

Ships float in the water at a level where mass of the displaced water equals the mass of the vessel, so that the downwards force of
gravity In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...
equals the upward force of
buoyancy Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the ...
. As a vessel is lowered into the water its weight remains constant but the corresponding weight of water displaced by its hull increases. If the vessel's mass is evenly distributed throughout, it floats evenly along its length and across its beam (width). A vessel's stability is considered in both this
hydrostatic Fluid statics or hydrostatics is the branch of fluid mechanics that studies the condition of the equilibrium of a floating body and submerged body "fluids at hydrostatic equilibrium and the pressure in a fluid, or exerted by a fluid, on an imme ...
sense as well as a
hydrodynamic In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids— liquids and gases. It has several subdisciplines, including '' aerodynamics'' (the study of air and other gases in motion) a ...
sense, when subjected to movement, rolling and pitching, and the action of waves and wind. Stability problems can lead to excessive pitching and rolling, and eventually capsizing and sinking.


Hydrodynamics

The advance of a vessel through water is resisted by the water. This resistance can be broken down into several components, the main ones being the friction of the water on the hull and wave making resistance. To reduce resistance and therefore increase the speed for a given power, it is necessary to reduce the wetted surface and use submerged hull shapes that produce low amplitude waves. To do so, high-speed vessels are often more slender, with fewer or smaller appendages. The friction of the water is also reduced by regular maintenance of the hull to remove the sea creatures and algae that accumulate there.
Antifouling Biofouling or biological fouling is the accumulation of microorganisms, plants, algae, or small animals where it is not wanted on surfaces such as ship and submarine hulls, devices such as water inlets, pipework, grates, ponds, and rivers that ...
paint is commonly used to assist in this. Advanced designs such as the
bulbous bow A bulbous bow is a protruding bulb at the bow (or front) of a ship just below the waterline. The bulb modifies the way the water flows around the hull, reducing drag and thus increasing speed, range, fuel efficiency, and stability. Large ships w ...
assist in decreasing wave resistance. A simple way of considering wave-making resistance is to look at the hull in relation to its wake. At speeds lower than the wave propagation speed, the wave rapidly dissipates to the sides. As the hull approaches the wave propagation speed, however, the wake at the bow begins to build up faster than it can dissipate, and so it grows in
amplitude The amplitude of a periodic variable is a measure of its change in a single period (such as time or spatial period). The amplitude of a non-periodic signal is its magnitude compared with a reference value. There are various definitions of am ...
. Since the water is not able to "get out of the way of the hull fast enough", the hull, in essence, has to climb over or push through the bow wave. This results in an
exponential Exponential may refer to any of several mathematical topics related to exponentiation, including: *Exponential function, also: **Matrix exponential, the matrix analogue to the above *Exponential decay, decrease at a rate proportional to value *Expo ...
increase in resistance with increasing speed. This
hull speed Hull speed or displacement speed is the speed at which the wavelength of a vessel's bow wave is equal to the waterline length of the vessel. As boat speed increases from rest, the wavelength of the bow wave increases, and usually its crest-to-t ...
is found by the formula: or, in
metric Metric or metrical may refer to: * Metric system, an internationally adopted decimal system of measurement * An adjective indicating relation to measurement in general, or a noun describing a specific type of measurement Mathematics In mathem ...
units: where ''L'' is the length of the waterline in feet or meters. When the vessel exceeds a speed/length ratio of 0.94, it starts to outrun most of its
bow wave A bow wave is the wave that forms at the bow of a ship when it moves through the water. As the bow wave spreads out, it defines the outer limits of a ship's wake. A large bow wave slows the ship down, is a risk to smaller boats, and in a harbor ...
, and the hull actually settles slightly in the water as it is now only supported by two wave peaks. As the vessel exceeds a speed/length ratio of 1.34, the hull speed, the wavelength is now longer than the hull, and the stern is no longer supported by the wake, causing the stern to squat, and the bow rise. The hull is now starting to climb its own bow wave, and resistance begins to increase at a very high rate. While it is possible to drive a displacement hull faster than a speed/length ratio of 1.34, it is prohibitively expensive to do so. Most large vessels operate at speed/length ratios well below that level, at speed/length ratios of under 1.0. For large projects with adequate funding, hydrodynamic resistance can be tested experimentally in a hull testing pool or using tools of
computational fluid dynamics Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid flows. Computers are used to perform the calculations required to simulate ...
. Vessels are also subject to
ocean surface wave In fluid dynamics, a wind wave, water wave, or wind-generated water wave, is a surface wave that occurs on the free surface of bodies of water as a result from the wind blowing over the water surface. The contact distance in the direction o ...
s and sea swell as well as effects of
wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ho ...
and
weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloud cover, cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmos ...
. These movements can be stressful for passengers and equipment, and must be controlled if possible. The rolling movement can be controlled, to an extent, by ballasting or by devices such as fin stabilizers. Pitching movement is more difficult to limit and can be dangerous if the bow submerges in the waves, a phenomenon called pounding. Sometimes, ships must change course or speed to stop violent rolling or pitching.


Lifecycle

A ship will pass through several stages during its career. The first is usually an initial contract to build the ship, the details of which can vary widely based on relationships between the
shipowner A ship-owner is the owner of a merchant vessel (commercial ship) and is involved in the shipping industry. In the commercial sense of the term, a shipowner is someone who equips and exploits a ship, usually for delivering cargo at a certain frei ...
s, operators,
designers A designer is a person who plans the form or structure of something before it is made, by preparing drawings or plans. In practice, anyone who creates tangible or intangible objects, products, processes, laws, games, graphics, services, or exp ...
and the shipyard. Then, the design phase carried out by a naval architect. Then the ship is constructed in a shipyard. After construction, the vessel is launched and goes into service. Ships end their careers in a number of ways, ranging from shipwrecks to service as a museum ship to the scrapyard.


Design

A vessel's design starts with a specification, which a
naval architect This is the top category for all articles related to architecture and its practitioners. {{Commons category, Architecture occupations Design occupations Occupations Occupation commonly refers to: *Occupation (human activity), or job, one's role ...
uses to create a project outline, assess required dimensions, and create a basic layout of spaces and a rough displacement. After this initial rough draft, the architect can create an initial hull design, a general profile and an initial overview of the ship's propulsion. At this stage, the designer can iterate on the ship's design, adding detail and refining the design at each stage. The designer will typically produce an overall plan, a general specification describing the peculiarities of the vessel, and construction blueprints to be used at the building site. Designs for larger or more complex vessels may also include sail plans, electrical schematics, and plumbing and ventilation plans. As environmental laws are becoming more strict, ship designers need to create their design in such a way that the ship, when it nears its end-of-term, can be disassembled or disposed easily and that waste is reduced to a minimum.


Construction

Ship construction takes place in a shipyard, and can last from a few months for a unit produced in series, to several years to reconstruct a wooden boat like the frigate ''Hermione'', to more than 10 years for an aircraft carrier. During
World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
, the need for cargo ships was so urgent that construction time for
Liberty Ships Liberty ships were a class of cargo ship built in the United States during World War II under the Emergency Shipbuilding Program. Though British in concept, the design was adopted by the United States for its simple, low-cost construction. Mass ...
went from initially eight months or longer, down to weeks or even days. Builders employed production line and prefabrication techniques such as those used in shipyards today. Hull materials and vessel size play a large part in determining the method of construction. The hull of a mass-produced fiberglass sailboat is constructed from a mold, while the steel hull of a cargo ship is made from large sections welded together as they are built. Generally, construction starts with the hull, and on vessels over about , by the laying of the keel. This is done in a
drydock A dry dock (sometimes drydock or dry-dock) is a narrow basin or vessel that can be flooded to allow a load to be floated in, then drained to allow that load to come to rest on a dry platform. Dry docks are used for the construction, maintenance, ...
or on land. Once the hull is assembled and painted, it is launched. The last stages, such as raising the superstructure and adding equipment and accommodation, can be done after the vessel is afloat. Once completed, the vessel is delivered to the customer.
Ship launching Ceremonial ship launching involves the performance of ceremonies associated with the process of transferring a vessel to the water. It is a nautical tradition in many cultures, dating back thousands of years, to accompany the physical pro ...
is often a ceremony of some significance, and is usually when the vessel is formally named. A typical small rowboat can cost under US$100, $1,000 for a small speedboat, tens of thousands of dollars for a cruising sailboat, and about $2,000,000 for a
Vendée Globe --> The Vendée Globe is a single-handed (solo) non-stop round the world yacht race. The race was founded by Philippe Jeantot in 1989, and since 1992 has taken place every four years. It is named after the Département of Vendée, in France ...
class sailboat. A trawler may cost $2.5 million, and a 1,000-person-capacity high-speed passenger ferry can cost in the neighborhood of $50 million. A ship's cost partly depends on its complexity: a small, general cargo ship will cost $20 million, a Panamax-sized
bulk carrier A bulk carrier or bulker is a merchant ship specially designed to transport unpackaged bulk cargo — such as grains, coal, ore, steel coils, and cement — in its cargo holds. Since the first specialized bulk carrier was built in 1852, eco ...
around $35 million, a
supertanker An oil tanker, also known as a petroleum tanker, is a ship designed for the bulk transport of oil or its products. There are two basic types of oil tankers: crude tankers and product tankers. Crude tankers move large quantities of unrefined ...
around $105 million and a large
LNG carrier An LNG carrier is a tank ship designed for transporting liquefied natural gas (LNG). History The first LNG carrier '' Methane Pioneer'' () carrying , classed by Bureau Veritas, left the Calcasieu River on the Louisiana Gulf coast on 25 January ...
nearly $200 million. The most expensive ships generally are so because of the cost of embedded electronics: a costs around $2 billion, and an aircraft carrier goes for about $3.5 billion.


Repair and conversion

Ships undergo nearly constant maintenance during their career, whether they be underway, pierside, or in some cases, in periods of reduced operating status between charters or shipping seasons. Most ships, however, require trips to special facilities such as a
drydock A dry dock (sometimes drydock or dry-dock) is a narrow basin or vessel that can be flooded to allow a load to be floated in, then drained to allow that load to come to rest on a dry platform. Dry docks are used for the construction, maintenance, ...
at regular intervals. Tasks often done at drydock include removing biological growths on the hull,
sandblasting Sandblasting, sometimes known as abrasive blasting, is the operation of forcibly propelling a stream of abrasive material against a surface under high pressure to smooth a rough surface, roughen a smooth surface, shape a surface or remove s ...
and repainting the hull, and replacing sacrificial anodes used to protect submerged equipment from corrosion. Major repairs to the propulsion and steering systems as well as major electrical systems are also often performed at dry dock. Some vessels that sustain major damage at sea may be repaired at a facility equipped for major repairs, such as a shipyard. Ships may also be converted for a new purpose:
oil tanker An oil tanker, also known as a petroleum tanker, is a ship designed for the bulk transport of oil or its products. There are two basic types of oil tankers: crude tankers and product tankers. Crude tankers move large quantities of unrefined cru ...
s are often converted into
floating production storage and offloading unit A floating production storage and offloading (FPSO) unit is a floating vessel used by the offshore oil and gas industry for the production and processing of hydrocarbons, and for the storage of oil. An FPSO vessel is designed to receive h ...
s.


End of service

Most ocean-going cargo ships have a life expectancy of between 20 and 30 years. A sailboat made of plywood or fiberglass can last between 30 and 40 years. Solid wooden ships can last much longer but require regular maintenance. Carefully maintained steel-hulled yachts can have a lifespan of over 100 years. As ships age, forces such as corrosion, osmosis, and rotting compromise hull strength, and a vessel becomes too dangerous to sail. At this point, it can be
scuttled Scuttling is the deliberate sinking of a ship. Scuttling may be performed to dispose of an abandoned, old, or captured vessel; to prevent the vessel from becoming a navigation hazard; as an act of self-destruction to prevent the ship from being ...
at sea or scrapped by
shipbreakers ''Shipbreakers'' is a 2004 documentary film. A co-production of the National Film Board of Canada with Storyline Entertainment directed by Michael Kot, the film explores the practice of ship breaking decommissioned vessels in Alang, India. Aw ...
. Ships can also be used as museum ships, or expended to construct
breakwaters A breakwater is a permanent structure constructed at a coastal area to protect against tides, currents, waves, and storm surges. Part of a coastal management system, breakwaters are installed to minimize erosion, and to protect anchorages, h ...
or
artificial reef An artificial reef is a human-created underwater structure, typically built to promote marine life in areas with a generally featureless bottom, to control erosion, block ship passage, block the use of trawling nets, or improve surfing. Many ...
s. Many ships do not make it to the scrapyard, and are lost in fires, collisions, grounding, or sinking at sea. The Allies lost some 5,150 ships during
World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
.


Measuring ships

One can measure ships in terms of length overall,
length between perpendiculars Length between perpendiculars (often abbreviated as p/p, p.p., pp, LPP, LBP or Length BPP) is the length of a ship along the summer load line from the forward surface of the stem, or main bow perpendicular member, to the after surface of the ster ...
, length of the ship at the waterline, beam (breadth), depth (distance between the crown of the weather deck and the top of the keelson),
draft Draft, The Draft, or Draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a vesse ...
(distance between the highest waterline and the bottom of the ship) and
tonnage Tonnage is a measure of the cargo-carrying capacity of a ship, and is commonly used to assess fees on commercial shipping. The term derives from the taxation paid on ''tuns'' or casks of wine. In modern maritime usage, "tonnage" specifically r ...
. A number of different tonnage definitions exist and are used when describing merchant ships for the purpose of tolls, taxation, etc. In Britain until
Samuel Plimsoll Samuel Plimsoll (10 February 1824 – 3 June 1898) was a British politician and social reformer, now best remembered for having devised the Plimsoll line (a line on a ship's hull indicating the maximum safe draught, and therefore the minimum fr ...
's Merchant Shipping Act of 1876, ship-owners could load their vessels until their decks were almost awash, resulting in a dangerously unstable condition. Anyone who signed on to such a ship for a voyage and, upon realizing the danger, chose to leave the ship, could end up in jail. Plimsoll, a
Member of Parliament A member of parliament (MP) is the representative in parliament of the people who live in their electoral district. In many countries with bicameral parliaments, this term refers only to members of the lower house since upper house members o ...
, realised the problem and engaged some
engineer Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limit ...
s to derive a fairly simple formula to determine the position of a line on the side of any specific ship's hull which, when it reached the surface of the water during loading of cargo, meant the ship had reached its maximum safe loading level. To this day, that mark, called the "
Plimsoll Line The waterline is the line where the hull of a ship meets the surface of the water. Specifically, it is also the name of a special marking, also known as an international load line, Plimsoll line and water line (positioned amidships), that indi ...
", exists on ships' sides, and consists of a
circle A circle is a shape consisting of all points in a plane that are at a given distance from a given point, the centre. Equivalently, it is the curve traced out by a point that moves in a plane so that its distance from a given point is con ...
with a horizontal line through the centre. On the Great Lakes of North America the circle is replaced with a diamond. Because different types of water (summer, fresh, tropical fresh, winter north Atlantic) have different densities, subsequent regulations required painting a group of lines forward of the Plimsoll mark to indicate the safe depth (or freeboard above the surface) to which a specific ship could load in water of various densities. Hence the "ladder" of lines seen forward of the Plimsoll mark to this day. This is called the " freeboard mark" or " load line mark" in the
marine industry Maritime transport (or ocean transport) and hydraulic effluvial transport, or more generally waterborne transport, is the transport of people ( passengers) or goods (cargo) via waterways. Freight transport by sea has been widely used throu ...
.


Ship pollution

Ship pollution is the pollution of air and water by
shipping Freight transport, also referred as ''Freight Forwarding'', is the physical process of transporting commodities and merchandise goods and cargo. The term shipping originally referred to transport by sea but in American English, it has been ...
. It is a problem that has been accelerating as trade has become increasingly globalized, posing an increasing threat to the world's oceans and waterways as
globalization Globalization, or globalisation (English in the Commonwealth of Nations, Commonwealth English; American and British English spelling differences#-ise, -ize (-isation, -ization), see spelling differences), is the process of foreign relation ...
continues. It is expected that "shipping traffic to and from the United States is projected to double by 2020." Because of increased traffic in ocean
port A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as H ...
s, pollution from ships also directly affects coastal areas. The pollution produced affects
biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...
, climate, food, and human health. However, the degree to which humans are polluting and how it affects the world is highly debated and has been a hot international topic for the past 30 years.


Oil spills

Oil spills have devastating effects on the environment. Crude oil contains
polycyclic aromatic hydrocarbons A polycyclic aromatic hydrocarbon (PAH) is a class of organic compounds that is composed of multiple aromatic rings. The simplest representative is naphthalene, having two aromatic rings and the three-ring compounds anthracene and phenanthrene. ...
(PAHs) which are very difficult to clean up, and last for years in the
sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sa ...
and marine environment. Marine species constantly exposed to PAHs can exhibit developmental problems, susceptibility to disease, and abnormal reproductive cycles. By the sheer amount of oil carried, modern oil tankers must be considered something of a threat to the environment. An oil tanker can carry of crude oil, or . This is more than six times the amount spilled in the widely known Exxon Valdez oil spill, ''Exxon Valdez'' incident. In this spill, the ship ran aground and dumped of oil into the ocean in March 1989. Despite efforts of scientists, managers, and volunteers, over 400,000 seabirds, about 1,000 sea otters, and immense numbers of fish were killed. The International Tanker Owners Pollution Federation has researched 9,351 accidental spills since 1974. According to this study, most spills result from routine operations such as loading cargo, discharging cargo, and taking on fuel oil. 91% of the operational oil spills were small, resulting in less than 7 tons per spill. Spills resulting from accidents like collisions, groundings, hull failures, and explosions are much larger, with 84% of these involving losses of over 700 tons. Following the ''Exxon Valdez'' spill, the United States passed the Oil Pollution Act of 1990 (OPA-90), which included a stipulation that all tankers entering its waters be Double-hulled tanker, double-hulled by 2015. Following the sinkings of ''Erika (tanker), Erika'' (1999) and ''Prestige oil spill, Prestige'' (2002), the European Union passed its own stringent anti-pollution packages (known as Erika I, II, and III), which require all tankers entering its waters to be double-hulled by 2010. The Erika packages are controversial because they introduced the new legal concept of "serious negligence".


Ballast water

When a large vessel such as a
container ship A container ship (also called boxship or spelled containership) is a cargo ship that carries all of its load in truck-size intermodal containers, in a technique called containerization. Container ships are a common means of commercial intermoda ...
or an oil tanker unloads cargo, seawater is pumped into other compartments in the hull to help stabilize and balance the ship. During loading, this ballast water is pumped out from these compartments. One of the problems with ballast water transfer is the transport of harmful organisms. Meinesz believes that one of the worst cases of a single invasive species causing harm to an ecosystem can be attributed to a seemingly harmless planktonic organism . ''Mnemiopsis leidyi'', a species of comb jelly that inhabits estuaries from the United States to the Valdés peninsula in Argentina along the
Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
coast, has caused notable damage in the Black Sea. It was first introduced in 1982, and thought to have been transported to the Black Sea in a ship's ballast water. The population of the comb jelly shot up exponentially and, by 1988, it was wreaking havoc upon the local fishing industry. "The anchovy catch fell from in 1984 to in 1993; sprat from in 1984 to in 1993; horse mackerel (disambiguation), horse mackerel from in 1984 to zero in 1993." Now that the comb jellies have exhausted the zooplankton, including fish larvae, their numbers have fallen dramatically, yet they continue to maintain a stranglehold on the ecosystem. Recently the comb jellies have been discovered in the Caspian Sea. Invasive species can take over once occupied areas, facilitate the spread of new diseases, introduce new Genetics, genetic material, alter landscapes and jeopardize the ability of native species to obtain food. "On land and in the sea, invasive species are responsible for about 137 billion dollars in lost revenue and management costs in the U.S. each year." Ballast and bilge discharge from ships can also spread human pathogens and other harmful diseases and toxins potentially causing health issues for humans and marine life alike. Discharges into coastal waters, along with other sources of marine pollution, have the potential to be toxic to marine plants, animals, and microorganisms, causing alterations such as changes in growth, disruption of hormone cycles, birth defects, suppression of the immune system, and disorders resulting in cancer, tumors, and genetic abnormalities or even death.


Exhaust emissions

exhaust gas, Exhaust emissions from ships are considered to be a significant source of air pollution. "Seagoing vessels are responsible for an estimated 14 percent of emissions of nitrogen from fossil fuels and 16 percent of the emissions of sulfur from petroleum uses into the atmosphere." In Europe ships make up a large percentage of the sulfur introduced to the air, "as much sulfur as all the cars, Truck, lorries and factories in Europe put together". "By 2010, up to 40% of air pollution over land could come from ships." Sulfur in the air creates acid rain which damages crops and buildings. When inhaled, sulfur is known to cause respiratory problems and increase the risk of a myocardial infarction, heart attack.


Ship breaking

Ship breaking or ship demolition is a type of ship disposal involving the breaking up of ships for scrap recycling, with the hulls being discarded in ship graveyards. Most ships have a lifespan of a few decades before there is so much wear that refitting and repair becomes uneconomical. Ship breaking allows materials from the ship, especially steel, to be reused. In addition to steel and other useful materials, however, ships (particularly older vessels) can contain many substances that are banned or considered dangerous in developed countries. Asbestos and polychlorinated biphenyls (PCBs) are typical examples. Asbestos was used heavily in ship construction until it was finally banned in most of the developed world in the mid 1980s. Currently, the costs associated with removing asbestos, along with the potentially expensive insurance and health risks, have meant that ship-breaking in most developed countries is no longer economically viable. Removing the metal for scrap can potentially cost more than the scrap value of the metal itself. In most of the developing world, however, shipyards can operate without the risk of Personal injury, personal injury lawsuits or Workers' compensation, workers' health claims, meaning many of these shipyards may operate with high health risks. Furthermore, workers are paid very low rates with no overtime or other allowances. Protective equipment is sometimes absent or inadequate. Dangerous vapors and fumes from burning materials can be inhaled, and dusty asbestos-laden areas around such breakdown locations are commonplace. Aside from the health of the yard workers, in recent years, ship breaking has also become an issue of major environmentalism, environmental concern. Many developing nations, in which ship breaking yards are located, have lax or no environmental law, enabling large quantities of highly toxic materials to escape into the environment and causing serious health problems among ship breakers, the local population and wildlife. Environmental campaign groups such as Greenpeace have made the issue a high priority for their campaigns.


See also

* Admiralty law * Airship * Auxiliary ship * Boat * Chartering (shipping) * Dynamic positioning * Environmental impact of shipping * Factory ship * Ferry * Flag state * Fluyt * Galleon * Galley * Glossary of nautical terms (A-L) * Glossary of nautical terms (M-Z) * Marine electronics * Marine fuel management * Maritime history * Mother ship * Naval architecture *
Naval ship A naval ship is a military ship (or sometimes boat, depending on classification) used by a navy. Naval ships are differentiated from civilian ships by construction and purpose. Generally, naval ships are Damage control, damage resilient a ...
* Navy * Nuclear marine propulsion * Propulsion * Sailing * Sailing ship * Sailor * Ship burial *
Ship transport Maritime transport (or ocean transport) and hydraulic effluvial transport, or more generally waterborne transport, is the transport of people ( passengers) or goods (cargo) via waterways. Freight transport by sea has been widely used throu ...
* Ship watching * Shipwreck * Spacecraft, Spaceship * Train ferry * Vessel safety survey * Warship * Watercraft * Whaler Model ships * Ship model * Ship model basin * Ship replica Lists * List of fictional ships * List of historical ship types * List of Panamax ports * List of largest cruise ships * List of largest ships by gross tonnage * List of longest ships * Lists of ships * Lists of shipwrecks Ship sizes * Aframax * Capesize * Chinamax * Handymax * Handysize * Maersk Triple E class * Malaccamax * Panamax * Q-Max * Seawaymax * Suezmax * Oil tanker, Ultra Large Crude Carrier * Valemax * Oil tanker, VLCC


Notes


References


Citations


Sources

* * * * * * * * * * * * * * * * * * * * * * * * {{Authority control Ships,