![Collision of Costa Concordia 24](https://upload.wikimedia.org/wikipedia/commons/8/80/Collision_of_Costa_Concordia_24.jpg)
A shipwreck is the wreckage of a
ship
A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished ...
that is located either beached on land or sunken to the bottom of a body of water. Shipwrecking may be intentional or unintentional. Angela Croome reported in January 1999 that there were approximately three million shipwrecks worldwide (an estimate rapidly endorsed by
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...
and other organizations).
When a ship's crew has died or abandoned the ship, and the ship has remained adrift but unsunk, they are instead referred to as
ghost ships
A ghost ship, also known as a phantom ship, is a vessel with no living crew aboard; it may be a fictional ghostly vessel, such as the ''Flying Dutchman'', or a physical derelict found adrift with its crew missing or dead, like the ''Mary Celes ...
.
Types
![Sparrow Hawk ship](https://upload.wikimedia.org/wikipedia/commons/4/47/Sparrow_Hawk_ship.jpg)
Historic wrecks are attractive to
maritime archaeologists because they preserve historical information: for example, studying the wreck of revealed information about seafaring, warfare, and life in the 16th century. Military wrecks, caused by a skirmish at sea, are studied to find details about the historic event; they reveal much about the battle that occurred. Discoveries of
treasure ships, often from the period of European
colonisation
Colonization, or colonisation, constitutes large-scale population movements wherein migrants maintain strong links with their, or their ancestors', former country – by such links, gain advantage over other inhabitants of the territory. When ...
, which sank in remote locations leaving few living witnesses, such as , do occur as well.
Some contemporary wrecks, such as the
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 crud ...
''Prestige'' or , are of interest primarily because of their potential harm to the environment. Other contemporary wrecks are scuttled in order to spur reef growth, such as and ''Ocean Freeze''. Many contemporary and historic wrecks, such as , are of interest to
recreational divers that dive to shipwrecks because they are interesting to explore, provide large habitats for many types of marine life, and have an interesting history.
Well known shipwrecks include the catastrophic ''
Titanic
RMS ''Titanic'' was a British passenger liner, operated by the White Star Line, which sank in the North Atlantic Ocean on 15 April 1912 after striking an iceberg during her maiden voyage from Southampton, England, to New York City, United ...
'', , , , , , or . There are also thousands of wrecks that were not lost at sea but have been abandoned or sunk. These abandoned, or derelict ships are typically smaller craft, such as fishing vessels. They may pose a hazard to navigation and may be removed by
port authorities
In Canada and the United States, a port authority (less commonly a port district) is a governmental or quasi-governmental public authority for a special-purpose district usually formed by a legislative body (or bodies) to operate ports and other t ...
.
Causes
![Vista Sur](https://upload.wikimedia.org/wikipedia/commons/4/4c/Vista_Sur.jpg)
Poor design, improperly stowed
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 ...
, navigation and other human errors leading to collisions (with another ship, the shoreline, an iceberg, etc.), bad weather,
fire
Fire is the rapid oxidation of a material (the fuel) in the exothermic chemical process of combustion, releasing heat, light, and various reaction Product (chemistry), products.
At a certain point in the combustion reaction, called the ignition ...
, and other causes can lead to accidental sinking. Intentional reasons for sinking a ship include: intending to form an
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 re ...
; destruction due to
war
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 regular o ...
fare,
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 ...
,
mutiny
Mutiny is a revolt among a group of people (typically of a military, of a crew or of a crew of pirates) to oppose, change, or overthrow an organization to which they were previously loyal. The term is commonly used for a rebellion among member ...
or
sabotage
Sabotage is a deliberate action aimed at weakening a polity, effort, or organization through subversion, obstruction, disruption, or destruction. One who engages in sabotage is a ''saboteur''. Saboteurs typically try to conceal their identitie ...
; using the vessel for
target practice
In the military and in shooting, target practice are exercises in which weapons are shot at a target. The purpose of such exercises is to improve the aim or the weapons handling expertise of the person firing the weapon.
Targets being shot at ...
; or removing a menace to navigation. A ship can be also used as
breakwater structure
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 ...
.
State of preservation
![The Wasa from the stern](https://upload.wikimedia.org/wikipedia/commons/b/bc/The_Wasa_from_the_stern.jpg)
Many factors determine the state of preservation of a wreck:
* the ship's construction materials
* the wreck becoming covered in sand or silt
* the
salinity
Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...
of the water the wreck is in
* the level of destruction involved in the ship's loss
* whether the components or
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 ...
of the wreck were
salvaged
* whether the wreck was demolished to clear a navigable channel
* the depth of water at the wreck site
* the strength of
tidal
Tidal is the adjectival form of tide.
Tidal may also refer to:
* ''Tidal'' (album), a 1996 album by Fiona Apple
* Tidal (king), a king involved in the Battle of the Vale of Siddim
* TidalCycles, a live coding environment for music
* Tidal (servic ...
currents or
wave action
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 of t ...
at the wreck site
* the exposure to surface weather conditions at the wreck site
* the presence of
marine life
Marine life, sea life, or ocean life is the plants, animals and other organisms that live in the salt water of seas or oceans, or the brackish water of coastal estuaries. At a fundamental level, marine life affects the nature of the planet. M ...
that consume the ship's fabric
* temperature
* the acidity (or
pH), and other chemical characteristics of the water at the site
The above - especially the stratification (silt/sand sediments piled up on the shipwrecks) and the damages caused by marine creatures - is better described as "stratification and contamination" of shipwrecks. The stratification not only creates another challenge for marine archaeology, but also a challenge to determine its primary state, i.e. the state that it was in when it sank.
Stratification includes several different types of sand and silt, as well as tumulus and encrustations. These "sediments" are tightly linked to the type of currents, depth, and the type of water (salinity, pH, etc.), which implies any chemical reactions that would affect potential cargo (such as wine, olive oil, spices, etc.).
Besides this geological phenomenon, wrecks also face the damage of marine creatures that create a home out of them, primarily octopuses and crustaceans. These creatures affect the primary state because they move, or break, any parts of the shipwreck that are in their way, thereby affecting the original condition of
amphorae
An amphora (; grc, ἀμφορεύς, ''amphoreús''; English plural: amphorae or amphoras) is a type of container with a pointed bottom and characteristic shape and size which fit tightly (and therefore safely) against each other in storag ...
, for example, or any other hollow places. Finally, in addition to the slight or severe destruction marine animals can create, there are also "external" contaminants, such as the artifacts on and around the wreck at
Pickles Reef
Pickles Reef is a small coral reef located within the Florida Keys National Marine Sanctuary. It lies to the southeast of Key Largo, to the south the Key Largo Existing Management Area and John Pennekamp Coral Reef State Park. Unlike many reefs ...
and the over-lapping wrecks at the
Molasses Reef Wreck
The Molasses Reef Shipwreck is the site of a ship which wrecked in the Turks and Caicos Islands early in the 16th century. It is the oldest wreck of a European ship in the Americas to have been scientifically excavated.Leshikar-Denton: 286Museu ...
, or contemporary pollution in bodies of water, that severely affect shipwrecks by changing the chemical structures, or further damaging what is left of a specific ship.
Despite these challenges, if the information retrieved does not appear to be sufficient, or a poor preservation is achieved, authors like J.A. Parker claim that it is the historical value of the shipwreck that counts as well as any slight piece of information or evidence that is acquired.
Construction materials
![The Wreck, by Knud-Andreassen Baade c](https://upload.wikimedia.org/wikipedia/commons/4/4a/The_Wreck%2C_by_Knud-Andreassen_Baade_c.1835.JPG)
Exposed
wood
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin th ...
en components decay quickly. Often the only wooden parts of ships that remain after a century are those that were buried in
silt
Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel when ...
or
sand
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...
soon after the sinking. An example of this is ''Mary Rose''.
Steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
and
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
, depending on their thickness, may retain the ship's structure for decades. As
corrosion
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...
takes place, sometimes helped by tides and weather, the structure collapses. Thick ferrous objects such as
cannon
A cannon is a large- caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder ...
s,
steam
Steam is a substance containing water in the gas phase, and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization ...
boiler
A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, central h ...
s or the
pressure vessel
A pressure vessel is a container designed to hold gases or liquids at a pressure substantially different from the ambient pressure.
Construction methods and materials may be chosen to suit the pressure application, and will depend on the size o ...
of a
submarine
A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...
often survive well underwater in spite of corrosion.
Propeller
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...
s,
condensers,
hinge
A hinge is a mechanical bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation: all other ...
s and port holes were often made from non-ferrous metals such as
brass
Brass is an alloy of copper (Cu) and zinc (Zn), in proportions which can be varied to achieve different mechanical, electrical, and chemical properties. It is a substitutional alloy: atoms of the two constituents may replace each other with ...
and
phosphor bronze
Phosphor bronze is a member of the family of copper alloys. It is composed of copper that is alloyed with 0.5–11% of tin and 0.01–0.35% phosphorus, and may contain other elements to confer specific properties (e.g. lead at 0.5–3.0% to form ...
, which do not corrode easily.
Salinity of water
Freshwater and low saline
Shipwrecks in some
freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...
lakes, such as 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 lakes ...
of North America, have remained intact with little degradation. In some sea areas, most notably in
Gulf of Bothnia
The Gulf of Bothnia (; fi, Pohjanlahti; sv, Bottniska viken) is divided into the Bothnian Bay and Bothnian Sea, and it is the northernmost arm of the Baltic Sea, between Finland's west coast ( East Bothnia) and the Sweden's east coast (West ...
and
Gulf of Finland
The Gulf of Finland ( fi, Suomenlahti; et, Soome laht; rus, Фи́нский зали́в, r=Finskiy zaliv, p=ˈfʲinskʲɪj zɐˈlʲif; sv, Finska viken) is the easternmost arm of the Baltic Sea. It extends between Finland to the north and E ...
, salinity is very low, and centuries-old wrecks have been preserved in reasonable condition. However,
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
found in fresh water cause the wood on ships to rot more quickly than in seawater unless it is deprived of oxygen. Two shipwrecks, and , have been at the bottom of
Lake Ontario
Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the U.S. state of New York. The Canada–United States border sp ...
since they sunk during a violent storm on August 8, 1813, during the
War of 1812
The War of 1812 (18 June 1812 – 17 February 1815) was fought by the United States of America and its indigenous allies against the United Kingdom and its allies in British North America, with limited participation by Spain in Florida. It bega ...
. They are in "remarkably good" condition.
Seawater
Wrecks typically decay rapidly when in
seawater
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has appro ...
. There are several reasons for this:
*
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
-based metals
corrode
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...
much more quickly in seawater because of the dissolved
salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...
present; the sodium and chloride
ion
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...
s chemically accelerate the process of metal oxidation which, in the case of ferrous metals, leads to
rust
Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron(III) oxides (Fe2O3·nH2O) and iron(III) oxide-hydroxide (FeO(OH ...
. Such cases are prominent on deep-water shipwrecks, such as
RMS ''Titanic'' (sank 1912), (sank 1915), and (sank 1941). However, there are some exceptions; ''
RMS Empress of Ireland
RMS ''Empress of Ireland'' was a British-built ocean liner that sank near the mouth of the Saint Lawrence River in Canada following a collision in thick fog with the Norwegian collier in the early hours of 29 May 1914. Although the ship was ...
'' (sank 1914) lies in the saltwater portion of the
St. Lawrence River
The St. Lawrence River (french: Fleuve Saint-Laurent, ) is a large river in the middle latitudes of North America. Its headwaters begin flowing from Lake Ontario in a (roughly) northeasterly direction, into the Gulf of St. Lawrence, connecting ...
, but is still in remarkably good condition.
* Unprotected wood in seawater is rapidly consumed by
shipworm
The shipworms are marine bivalve molluscs in the family Teredinidae: a group of saltwater clams with long, soft, naked bodies. They are notorious for boring into (and commonly eventually destroying) wood that is immersed in sea water, including ...
s and small wood-boring sea creatures. Shipworms found in higher salinity waters, such as the
Caribbean
The Caribbean (, ) ( es, El Caribe; french: la Caraïbe; ht, Karayib; nl, De Caraïben) is a region of the Americas that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean Se ...
, are notorious for boring into wooden structures that are immersed in sea water and can completely destroy the hull of a wooden shipwreck.
Loss, salvage, and demolition
![SS Austria shipwreck](https://upload.wikimedia.org/wikipedia/commons/3/3c/SS_Austria_shipwreck.jpg)
An important factor in the condition of the wreck is the level of destruction at the time of the loss or shortly afterwards due to the nature of the loss, salvage or later demolition.
Examples of severe destruction at the time of loss are:
* Being blown onto a beach, reef, or rocks during a storm, termed "grounding" (e.g., )
* Collision with another ship (e.g., )
* Catastrophic explosion (e.g., ), steamship boilers often explode when water covers them during the process of sinking
* Fire that burns for a long time before the ship sinks (e.g., )
* Foundering, i.e., taking in so much water that buoyancy is lost and the ship sinks (e.g., RMS ''Titanic'' and HMHS ''Britannic''); some ships with a dense cargo (e.g., iron ore) may break up when sinking quickly and hitting a rocky seabed
* Enemy action from
aerial bomb
An aerial bomb is a type of explosive or incendiary weapon intended to travel through the air on a predictable trajectory. Engineers usually develop such bombs to be dropped from an aircraft.
The use of aerial bombs is termed aerial bombing.
...
s or
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 ...
es that may cause destruction before sinking (e.g., the and )
After the loss, the vessel's owners may attempt to
salvage valuable parts of the ship and its cargo. This operation can cause further damage.
Shipwrecks in shallow water near busy shipping lanes are often demolished or removed to reduce the danger to other vessels. On charts, some wreck symbols have a line under the symbol with a depth mark, which indicates the water depth above the wreck.
Depth, tide and weather
On the seabed, wrecks are slowly broken up by the forces of
wave action
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 of t ...
caused by the weather and currents caused by
tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravity, gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another.
Tide t ...
s. Also more highly oxygenated water, which promotes
corrosion
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...
, reduces the strength of ferrous structural materials of the ship. Deeper wrecks are likely to be protected by less exposure to water movement and by lower levels of oxygen in water.
Temperature
Extreme cold (such as in a
glacial-fed lake,
Arctic
The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenla ...
waters, 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 lakes ...
, etc.) slows the degradation of organic ship materials. Decay, corrosion and marine encrustation are inhibited or largely absent in cold waters.
Marine pollution
Many modern shipwrecks contribute to
marine pollution
Marine pollution occurs when substances used or spread by humans, such as industrial waste, industrial, agricultural pollution, agricultural and municipal solid waste, residential waste, particle (ecology), particles, noise, excess carbon dioxid ...
, mainly as sources of significant
oil spill
An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially the marine ecosystem, due to human activity, and is a form of pollution. The term is usually given to marine oil spills, where oil is released into th ...
s.
A 2005 survey of shipwrecks since 1890 found that over 8,500 of the submerged wrecks may still contain oil. Oil spills can have devastating effects on marine and coastal environments as well as fisheries. In addition to being toxic to marine life,
polycyclic aromatic hydrocarbon
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. ...
s (PAHs), found in
crude oil
Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crude ...
, 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, sand an ...
and marine environment.
Shipwreck pollution may also originate with a ship's cargo or munitions,
such as
unexploded ordnance or
chemical weapon
A chemical weapon (CW) is a specialized munition that uses chemicals formulated to inflict death or harm on humans. According to the Organisation for the Prohibition of Chemical Weapons (OPCW), this can be any chemical compound intended as a ...
s canisters. German trawler
V 1302 ''John Mahn'', sunk in the
North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...
in 1942,
has multiple unexploded
depth charges
A depth charge is an anti-submarine warfare (ASW) weapon. It is intended to destroy a submarine by being dropped into the water nearby and detonating, subjecting the target to a powerful and destructive hydraulic shock. Most depth charges use h ...
on board which render the wreck hazardous.
Samples taken from the wreck and nearby sediment show the presence of
heavy metals
upright=1.2, Crystals of osmium, a heavy metal nearly twice as dense as lead">lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead
Heavy metals are generally defined as ...
like nickel and copper,
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. P ...
,
arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but ...
and explosive compounds into surrounding waters, which have changed the local microbial ecology.
Natural deterioration process
![Quartette 03 noaa casserley](https://upload.wikimedia.org/wikipedia/commons/1/11/Quartette_03_noaa_casserley.jpg)
Iron and steel wrecks are subject to corrosion, which is most rapid in shallow sea water where the salinity induces galvanic corrosion, oxygen content is high and water movement replenishes the oxygen rapidly. In deeper water and in still water the corrosion rates can be greatly reduced. Corrosion rates of iron and steel are also reduced when concretions, solid layers of rust, or layers of marine organisms separate the metal from the ambient water, and encourage the development of a layer of relatively stable black oxide in the hypoxic layers.
Ships that sink upright onto a sand bottom tend to settle into the sand to a similar level to that at which they would normally float at the surface. The thinner materials of the upper works tend to break up first, followed by the decks and deck beams, and the hull sides unsupported by bulkheads. The bow and stern may remain relatively intact for longer as they are usually more heavily constructed. Heavy machinery like boilers, engines, pumps, winches, propellers, propeller shafts, steering gear, anchors and other heavy fittings also last longer and can provide support to the remaining hull, or cause it to collapse more rapidly. Vessels that come to rest upside down on a yielding seabed can be relatively stable, although the upper decks usually collapse under the load and machinery and fittings fall. Wrecks that rest on their side tend to deteriorate quickly, as the loads are not what they were designed to support, and poorly supported hull sides give way fairly soon and the wreckage collapses. Wrecks supported by a rocky seabed tend to collapse over and around the rocks relatively rapidly. Submarines tend to last longer as they are built much more strongly to withstand the working loads of external pressure, and may last for centuries.
Value
A shipwreck may have value in several forms:
*Cultural heritage,
*Recreational diving and other tourism attraction
*scientific, educational and monetary values
**Artificial reefs
**Monetary value of salvageable cargo and components
Salvage
Often, attempts are made to salvage shipwrecks, particularly those recently wrecked, to recover the whole or part of the ship, its cargo, or its equipment. An example was the salvage of the
scuttled German High Seas Fleet at Scapa Flow in the 1920s and 1930s. The unauthorized salvage of wrecks is called
wrecking.
Legal aspects
Shipwreck law determines important legal questions regarding wrecks, perhaps the most important question being the question of ownership. Legally wrecks are divided into ''wreccum maris'' (material washed ashore after a shipwreck) and ''adventurae maris'' (material still at sea), which are treated differently by some, but not all, legal systems.
![Nanking Cargo kijkdag (1986)](https://upload.wikimedia.org/wikipedia/commons/1/1a/Nanking_Cargo_kijkdag_%281986%29.jpg)
Wrecks are often considered separately from their cargo. For example, in the British case of ''
Lusitania
Lusitania (; ) was an ancient Iberian Roman province located where modern Portugal (south of the Douro river) and
a portion of western Spain (the present Extremadura and the province of Salamanca) lie. It was named after the Lusitani or Lusita ...
''
986
Year 986 ( CMLXXXVI) was a common year starting on Friday (link will display the full calendar) of the Julian calendar.
Events
By place
Byzantine Empire
* August 17 – Battle of the Gates of Trajan: Emperor Basil II leads a Byz ...
QB 384 it was accepted that the remains of the vessel itself were owned by the insurance underwriters who had paid out on the vessel as a total loss by virtue of the law of
subrogation
Subrogation is the assumption by a third party (such as a second creditor or an insurance company) of another party's legal right to collect a debt or damages. It is a legal doctrine whereby one person is entitled to enforce the subsisting or reviv ...
(who subsequently sold their rights), but that the property aboard the wreck still belonged to its original owners or their heirs.
Military wrecks, however, remain under the jurisdictionand hence protectionof the government that lost the ship, or that government's successor. Hence, a German
U-boat
U-boats were naval submarines operated by Germany, particularly in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic warfare role ...
from World War II still technically belongs to the German government, although
Nazi Germany
Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...
(the government at the time) is long-defunct. Many military wrecks are also protected by virtue of being
war grave
A war grave is a burial place for members of the armed forces or civilians who died during military campaigns or operations.
Definition
The term "war grave" does not only apply to graves: ships sunk during wartime are often considered to b ...
s.
However, many legal systems allow the rights of salvors to override the rights of the original owners of a wreck or its cargo. As a general rule, non-historic civilian shipwrecks are considered fair game for salvage. Under international
maritime law
Admiralty law or maritime law is a body of law that governs nautical issues and private maritime disputes. Admiralty law consists of both domestic law on maritime activities, and private international law governing the relationships between priva ...
, for shipwrecks of a certain age, the original owner may have lost all claim to the cargo. Anyone who finds the wreck can then file a salvage claim on it and place a lien on the vessel, and subsequently mount a salvage operation (see
Finders, keepers
Finders, keepers, sometimes extended as the children's rhyme finders, keepers; losers, weepers, is an English adage with the premise that when something is unowned or abandoned, whoever finds it first can claim it for themself permanently. The ph ...
). The State of North Carolina questionably claims "all photographs, video recordings, or other documentary materials of a derelict vessel or shipwreck or its contents, relics, artifacts, or historic materials in the custody of any agency of North Carolina government or its subdivisions" to be its property.
Some countries assert claims to all wrecks within their territorial waters, irrespective of the interest of the original owner or the salvor.
![Napolibeached](https://upload.wikimedia.org/wikipedia/commons/8/85/Napolibeached.jpg)
Some legal systems regard a wreck and its cargo to be abandoned if no attempt is made to salvage them within a certain period of time. English law has usually resisted this notion (encouraged by an extremely large maritime insurance industry, which asserts claims in respect of shipwrecks which it has paid claims on), but it has been accepted to a greater or lesser degree in an Australian case and in a Norwegian case.
The American courts have been inconsistent between states and at Federal level. Under Danish law, all shipwrecks over 150 years old belong to the state if no owner can be found. In Spain, wrecks vest in the state if not salvaged within 3 years. In Finland, all property on board shipwrecks over 100 years old vests in the state.
The British
Protection of Wrecks Act
The Protection of Wrecks Act 1973 (c. 33) is an Act of the Parliament of the United Kingdom which provides protection for designated shipwrecks.
Section 1 of the act provides for wrecks to be designated because of historical, archaeological or ...
, enacted to protect historic wrecks, controls access to wrecks such as
Cattewater Wreck
Cattewater Wreck is a wooden three-masted, skeleton-built vessel, one of many ships that have wrecked in Cattewater, Plymouth Sound, England. This wreck is close to the entrance of Sutton Harbour, its name is still unknown but it is believed to ...
which can only be visited or investigated under licence. The British
Protection of Military Remains Act 1986
Protection is any measure taken to guard a thing against damage caused by outside forces. Protection can be provided to physical objects, including organisms, to systems, and to intangible things like civil and political rights. Although th ...
also restricts access to wrecks which are sensitive as
war grave
A war grave is a burial place for members of the armed forces or civilians who died during military campaigns or operations.
Definition
The term "war grave" does not only apply to graves: ships sunk during wartime are often considered to b ...
s. The Protection of Military Remains Act in some cases creates a blanket ban on all diving; for other wrecks divers may visit provided they do not touch, interfere with or penetrate the wreck. In the United States, shipwrecks in state waters are regulated by the
Abandoned Shipwrecks Act
The Abandoned Shipwrecks Act is a piece of United States legislation passed into law in 1988 meant to protect historic shipwrecks in US waters from treasure hunters and unauthorised salvagers by transferring the title to the wreck to the US sta ...
of 1987. This act is much more lenient in allowing more open access to the shipwrecks.
Following the beaching of , as a result of severe damage incurred during European storm
Kyrill, there was confusion in the press and by the authorities about whether people could be prevented from helping themselves to the
flotsam
In maritime law, flotsam'','' jetsam'','' lagan'','' and derelict are specific kinds of shipwreck. The words have specific nautical meanings, with legal consequences in the law of admiralty and marine salvage. A shipwreck is defined as the rema ...
which was washed up on the beaches at
Branscombe
Branscombe is a village in the East Devon district of the English County of Devon.
The parish covers . Its permanent population in 2009 was estimated at 513 by the Family Health Services Authority, reducing to 507 at the 2011 Census. It is loc ...
. Many people took advantage of the confusion and helped themselves to the cargo. This included many
BMW motorbikes and empty wine casks as well as bags of disposable nappies (
diapers
A diaper /ˈdaɪpə(r)/ (American and Canadian English) or a nappy (Australian English, British English, and Hiberno-English) is a type of underwear that allows the wearer to urinate or defecate without using a toilet, by absorbing or conta ...
). The legal position under the
Merchant Shipping Act 1995
The Merchant Shipping Act 1995 is an Act of Parliament passed in the United Kingdom in 1995. It consolidated much of the UK's maritime legislation, repealing several Acts in their entirety and provisions in many more, some dating back to the mid ...
is that any such finds and recovery must be reported within 28 days to the
Receiver of Wreck
The Receiver of Wreck is an official who administers law dealing with maritime wrecks and salvage in some countries having a British administrative heritage. In the United Kingdom, the Receiver of Wreck is also appointed to retain the possession o ...
. Failure to do so is an offence under the Merchant Shipping Act and can result in a criminal record for
theft by finding
Theft by finding occurs when someone chances upon an object which seems abandoned and takes possession of the object but fails to take steps to establish whether the object is genuinely abandoned and not merely lost or unattended. In some jurisdi ...
. After several days, the police and Receiver of Wreck, in conjunction with the landowner and the contracted
salvors, established a cordon to prevent access to the beach. A similar situation occurred after the wreck of in 1997.
Historic wrecks (often but not always defined as being more than 50 years of age) are often protected from pillaging and looting through national laws protecting cultural heritage. Internationally they may be protected by a State ratifying the
. In this case pillaging is not allowed. One such example is which is undergoing archaeological recovery by the North Carolina Department of Cultural Resources near Beaufort Inlet, NC.
An important international convention aiming at the protection of underwater cultural heritage (including shipwrecks) is the Convention on the Protection of the Underwater Cultural Heritage.
The 2001 UNESCO Convention on the Protection of the Underwater Cultural Heritage represents the international community's response to the increasing looting and destruction of underwater cultural heritage. It forms part of a group of UNESCO standard setting instruments regarding the domain of cultural heritage, encompassing seven conventions adopted by UNESCO Member States, which constitute a coherent and complementary body guaranteeing a complete protection of all forms of cultural heritage.
The UNESCO 2001 Convention is an international treaty aimed exclusively at the protection of underwater cultural heritage and the facilitation of international cooperation in this regard. It does not change sovereignty rights of States or regulate the ownership of wrecks or submerged ruins.
Notable salvages
In 2011, the most valuable cargo of a sunken shipwreck was identified near the western edge of the
Celtic Sea
The Celtic Sea ; cy, Y Môr Celtaidd ; kw, An Mor Keltek ; br, Ar Mor Keltiek ; french: La mer Celtique is the area of the Atlantic Ocean off the southern coast of Ireland bounded to the east by Saint George's Channel; other limits includ ...
. This World War II era sinking of led to a treasure almost deep.
A U.S. federal court and a panel from the United States Court of Appeals for the Eleventh Circuit have upheld the Spanish claim to the contents of the ship ; Spain took control of the treasure in February 2012. A very small number of coins and effects recovered from the ship were deposited in Gibraltar, because they showed clear signs coherent with an internal explosion on the ship and thus confirmed Spanish claims to the wreck being that of the Nuestra Señora de las Mercedes. They were not returned to Spain until 2013, when a court finally ordered Odyssey Marine to return the missing pieces.
Archaeologist
Valerios Stais
Valerios Stais ( el, Βαλέριος Στάης; b. Kythira 1857 – d. Athens 1923) was a Greek archaeologist. He initially studied medicine but later switched to archaeology obtaining his Doctorate from the University of Halle (Saale) in 1885 ...
discovered one of the most notable instruments of time keeping and prediction of celestial events off the coast of the Greek island Antikythera on May 17, 1902. The device, known as the
Antikythera Mechanism
The Antikythera mechanism ( ) is an Ancient Greece, Ancient Greek hand-powered orrery, described as the oldest example of an analogue computer used to predict astronomy, astronomical positions and eclipses decades in advance. It could also be ...
, is perhaps the earliest example of what would be known as today as an
analog computer
An analog computer or analogue computer is a type of computer that uses the continuous variation aspect of physical phenomena such as electrical, mechanical, or hydraulic quantities (''analog signals'') to model the problem being solved. In c ...
, and the technology it encompasses predates any other recorded description by hundreds or thousands of years.
Gallery
Shipwreck sis.png, Shipwreck on a shore near Gytheio
Gytheio ( el, Γύθειο, ) or Gythio, also the ancient Gythium or Gytheion ( grc, Γύθειον), is a town on the eastern shore of the Mani Peninsula, and a former municipality in Laconia, Peloponnese, Greece. Since the 2011 local government ...
, Greece
Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...
Wrecked fishing boats, Finnmark.jpg, Wrecked fishing boats in Finnmark
Finnmark (; se, Finnmárku ; fkv, Finmarku; fi, Ruija ; russian: Финнмарк) was a county in the northern part of Norway, and it is scheduled to become a county again in 2024.
On 1 January 2020, Finnmark was merged with the neighbouri ...
, North Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...
Assalama.jpg, The ferry ''Assalama'' wrecked off of Tarfaya
Tarfaya ( ar, طرفاية - ''Ṭarfāya''; ber, ⵟⵔⴼⴰⵢⴰ) is a coastal Moroccan town, located at the level of Cape Juby, in western Morocco, on the Atlantic coast. It is located about 890 km southwest of the capital Rabat, and ...
, Morocco
Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...
ShipWreckMahenoFraserIsland.jpg, Ship wreck of , Fraser Island
Fraser Island (Butchulla: ) is a World Heritage-listed island along the south-eastern coast in the Wide Bay–Burnett region, Queensland, Australia. The island is approximately north of the state capital, Brisbane, and is within the Fraser ...
, Australia
FrotamericaShipWreck.jpg, Shipwreck of ''Frotamerica'' at the west coast of Namibia
Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...
File:A piece of Shipwreck.jpg, A piece of Shipwreck of Portuguese stranded deep sea-takers 1975 Luanda
File:A Piece of history.jpg, A Shipwreck in Luanda
See also
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Conservation and restoration of shipwreck artifacts
The conservation and restoration of shipwreck artifacts is the process of caring for cultural heritage that has been part of a shipwreck. Oftentimes these cultural artifacts have been underwater for a great length of time. Without conservation, m ...
*
* (Superseded by the ''
Underwater Cultural Heritage Act 2018
The ''Underwater Cultural Heritage Act 2018'' is an Australian Act of Parliament designed "to protect shipwrecks, sunken aircraft and their associated artefacts, that occurred 75 or more years ago, regardless of whether their location is known ...
'')
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References
Further reading
* ; Vol.1 - The South West ; Vol.2 - The South Coast,; Vol.3 - The East Coast,; Vol.4 - Scotland, ; Vol.5 - West Coast & Wales, ; Vol. 6- Ireland (all)
*
External links
UNESCO 2001 Convention on the Protection of the Underwater Cultural HeritageWreckSite.eu worldwide database of + 105,000 wrecks with history, maritime charts and GPS positions (subscription required)
Wreck Diving in the Graveyard of the Atlantic Courthouse News
N.C Supreme Court revives lawsuit over Blackbeard’s ship and lost Spanish treasure ship Fayetteville Observer
{{Authority control
Law of the sea