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A Formula 16 beachable catamaran Powered catamaran passenger ferry at Salem, Massachusetts, United States A catamaran () (informally, a "cat") is a multi-hulled
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 sai ...
featuring two parallel hulls of equal size. It is a geometry-stabilized craft, deriving its stability from its wide beam, rather than from a ballasted
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 ...
as with a
monohull right A monohull is a type of boat having only one hull, unlike multihulled boats which can have two or more individual hulls connected to one another. Fundamental concept Among the earliest hulls were simple logs, but these were generally unsta ...
boat. Catamarans typically have less hull volume, smaller displacement, and shallower
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 ...
(draught) than monohulls of comparable length. The two hulls combined also often have a smaller hydrodynamic resistance than comparable monohulls, requiring less propulsive power from either sails or motors. The catamaran's wider stance on the water can reduce both heeling and wave-induced motion, as compared with a monohull, and can give reduced wakes. Catamarans were invented by the
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 Au ...
which enabled their expansion to the islands of the
Indian Indian or Indians may refer to: Peoples South Asia * Indian people, people of Indian nationality, or people who have an Indian ancestor ** Non-resident Indian, a citizen of India who has temporarily emigrated to another country * South Asia ...
and
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 conti ...
s. Catamarans range in size from small
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 chose ...
or
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 ...
vessels to large naval ships and
roll-on/roll-off Roll-on/roll-off (RORO or ro-ro) ships are cargo ships designed to carry wheeled cargo, such as cars, motorcycles, trucks, semi-trailer trucks, buses, trailers, and railroad cars, that are driven on and off the ship on their own wheels or using ...
car ferries. The structure connecting a catamaran's two hulls ranges from a simple frame strung with webbing to support the crew to a bridging superstructure incorporating extensive cabin and/or cargo space.


History

Catamarans from
Oceania Oceania (, , ) is a geographical region that includes Australasia, Melanesia, Micronesia, and Polynesia. Spanning the Eastern and Western hemispheres, Oceania is estimated to have a land area of and a population of around 44.5 million ...
and
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 ...
became the inspiration for modern catamarans. Until the 20th century catamaran development focused primarily on sail-driven concepts.


Etymology

The word "catamaran" is derived from the Tamil word, ''
kattumaram Kattumaram (கட்டுமரம்) is a traditional Tamil watercraft used in the Coast of Southern India, Sri Lanka, and Bangladesh,. They are characterized by being made from three to seven tree trunks tied together with fiber lashing ...
'' (கட்டுமரம்), which means "logs bound together" and is a type of single-hulled raft made of three to seven tree trunks lashed together. The term has evolved in English usage to refer to double-hulled vessels.


Development in Oceania and Asia

left, Succession of forms in the development of the Austronesian boat (Mahdi, 1999) Catamaran-type vessels were an early technology of the
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 Au ...
. Early researchers like Heine-Geldern (1932) and Hornell (1943) once believed that catamarans evolved from
outrigger canoe Outrigger boats are various watercraft featuring one or more lateral support floats known as outriggers, which are fastened to one or both sides of the main hull. They can range from small dugout canoes to large plank-built vessels. Outrigger ...
s, but modern authors specializing in Austronesian cultures like Doran (1981) and Mahdi (1988) now believe it to be the opposite. '' Polynesian_Multihull.html"__"title="Polynesian_culture.html"_;"title="Hōkūleʻa'',_a_modern_replica_of_a_Polynesian_culture">Polynesian_Multihull">double-hulled_ A_double_hull_is_a__ship_hull_design_and_construction_method_where_the_bottom_and_sides_of_the_ship_have_two_complete_layers_of_watertight_hull_surface:_one_outer_layer_forming_the_normal_hull_of_the_ship,_and_a_second_inner_hull_which_is_some_dis_...
_
Polynesian_Multihull.html"__"title="Polynesian_culture.html"_;"title="Hōkūleʻa'',_a_modern_replica_of_a_Polynesian_culture">Polynesian_Multihull">double-hulled_ A_double_hull_is_a__ship_hull_design_and_construction_method_where_the_bottom_and_sides_of_the_ship_have_two_complete_layers_of_watertight_hull_surface:_one_outer_layer_forming_the_normal_hull_of_the_ship,_and_a_second_inner_hull_which_is_some_dis_...
_ voyaging_Outrigger_canoe.html"__"title="Polynesian_navigation.html"_;"title="Polynesian_culture">Polynesian_Multihull.html"__"title="Polynesian_culture.html"_;"title="Hōkūleʻa'',_a_modern_replica_of_a_Polynesian_culture">Polynesian_Multihull">double-hulled_ A_double_hull_is_a__ship_hull_design_and_construction_method_where_the_bottom_and_sides_of_the_ship_have_two_complete_layers_of_watertight_hull_surface:_one_outer_layer_forming_the_normal_hull_of_the_ship,_and_a_second_inner_hull_which_is_some_dis_...
_Polynesian_navigation">voyaging_Outrigger_canoe">canoe_ A_canoe_is_a_lightweight_narrow__water_vessel,_typically_pointed_at_both_ends_and_open_on_top,_propelled_by_one_or_more_seated_or_kneeling_paddlers_facing_the_direction_of_travel_and_using_a_single-bladed__paddle. In_British_English,_the_ter_...
—an_Austronesian_peoples.html" ;"title="Polynesian_navigation">voyaging_Outrigger_canoe.html" "title="Polynesian_navigation.html" ;"title="Polynesian_culture">Polynesian_Multihull.html" "title="Polynesian_culture.html" ;"title="Hōkūleʻa'', a modern replica of a Polynesian culture">Polynesian Multihull">double-hulled A double hull is a ship hull design and construction method where the bottom and sides of the ship have two complete layers of watertight hull surface: one outer layer forming the normal hull of the ship, and a second inner hull which is some dis ...
Polynesian navigation">voyaging Outrigger canoe">canoe A canoe is a lightweight narrow water vessel, typically pointed at both ends and open on top, propelled by one or more seated or kneeling paddlers facing the direction of travel and using a single-bladed paddle. In British English, the ter ...
—an Austronesian peoples">Austronesian innovation Two canoes bound together developed directly from minimal raft technologies of two logs tied together. Over time, the double-hulled canoe form developed into the asymmetric double canoe, where one hull is smaller than the other. Eventually the smaller hull became the prototype
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 ...
, giving way to the single outrigger canoe, then to the reversible single outrigger canoe. Finally, the single outrigger types developed into the double outrigger canoe (or
trimaran A trimaran (or double-outrigger) is a multihull boat that comprises a main hull and two smaller outrigger hulls (or "floats") which are attached to the main hull with lateral beams. Most modern trimarans are sailing yachts designed for recreatio ...
s). This would also explain why older Austronesian populations in
Island 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 ...
tend to favor double outrigger canoes, as it keeps the boats stable when tacking. But they still have small regions where catamarans and single-outrigger canoes are still used. In contrast, more distant outlying descendant populations in
Oceania Oceania (, , ) is a geographical region that includes Australasia, Melanesia, Micronesia, and Polynesia. Spanning the Eastern and Western hemispheres, Oceania is estimated to have a land area of and a population of around 44.5 million ...
,
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 Afric ...
, and the
Comoros The Comoros,, ' officially the Union of the Comoros,; ar, الاتحاد القمري ' is an independent country made up of three islands in southeastern Africa, located at the northern end of the Mozambique Channel in the Indian Ocean. It ...
, retained the double-hull and the single outrigger canoe types, but the technology for double outriggers never reached them (although it exists in western
Melanesia Melanesia (, ) is a subregion of Oceania in the southwestern Pacific Ocean. It extends from Indonesia's New Guinea in the west to Fiji in the east, and includes the Arafura Sea. The region includes the four independent countries of Fiji, V ...
). To deal with the problem of the instability of the boat when the outrigger faces leeward when tacking, they instead developed the
shunting Shunting may refer to: * Ribosome shunting, a mechanism in protein biosynthesis * Shunting (rail), a rail transport operation * Shunting (neurophysiology), a concept in neurophysiology * Shunting (sailing), a maneuver for sailing upwind See a ...
technique in sailing, in conjunction with reversible single-outriggers. Despite their being the more "primitive form" of outrigger canoes, they were nonetheless effective, allowing seafaring Polynesians to voyage to distant Pacific islands.


Traditional catamarans

The following is a list of traditional Austronesian catamarans: *
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 ...
: :*
Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consis ...
: ''
Drua Drua, also known as na drua, n'drua, ndrua or waqa tabu ("sacred canoe", ), is a double-hull sailing boat that originated in the south-western Pacific islands. Druas do not tack but rather shunt (stern becomes the bow and vice versa). Both ends ...
'' (or ''waqa tabu'') :*
Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...
: ''
Lakatoi Lakatoi (also Lagatoi) are double-hulled sailing watercraft of Papua New Guinea. They are named in the Motu language and traditionally used in the Hiri trade cycle. Gallery File:Picturesque New Guinea Plate V (a) - Loading Lakatoi, Port More ...
'' :*
Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...
: '' Hamatafua'', '' kalia'', ''
tongiaki Tongiaki are native watercraft of Tonga. They are double-hulled canoes in the Austronesian tradition, similar to catamarans. See also *outrigger canoe Outrigger boats are various watercraft featuring one or more lateral support floats known a ...
'' *
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 ...
:*
Cook Islands ) , image_map = Cook Islands on the globe (small islands magnified) (Polynesia centered).svg , capital = Avarua , coordinates = , largest_city = Avarua , official_languages = , lan ...
: ''
Vaka katea Vaka katea are the traditional sailing double canoe watercraft of the Cook Islands. See also * Rarotonga Rarotonga is the largest and most populous of the Cook Islands. The island is volcanic, with an area of , and is home to almost 75% of the ...
'' :*
Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
: '' Waʻa kaulua'' :*
Marquesas The Marquesas Islands (; french: Îles Marquises or ' or '; Marquesan: ' (North Marquesan) and ' (South Marquesan), both meaning "the land of men") are a group of volcanic islands in French Polynesia, an overseas collectivity of France in t ...
: '' Vaka touʻua'' :*
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 coun ...
: ''
Waka hourua Waka may refer to: Culture and language * Waka (canoe), a Polynesian word for canoe; especially, canoes of the Māori of New Zealand ** Waka ama, a Polynesian outrigger canoe ** Waka hourua, a Polynesian ocean-going canoe ** Waka taua, a Māori ...
'' :*
Samoa Samoa, officially the Independent State of Samoa; sm, Sāmoa, and until 1997 known as Western Samoa, is a Polynesian island country consisting of two main islands ( Savai'i and Upolu); two smaller, inhabited islands ( Manono and Apolima); ...
: '' ʻAlia'', ''
amatasi Amatasi are a type of Samoan double-hulled watercraft. Its sails were woven pandanus leaves tied to 2 spars. The hull was sometimes built of planks. Lashed together, large double canoes long could carry 25 men on journeys of hundreds of miles. Se ...
'', '' va'a-tele'' :*
Society Islands The Society Islands (french: Îles de la Société, officially ''Archipel de la Société;'' ty, Tōtaiete mā) are an archipelago located in the South Pacific Ocean. Politically, they are part of French Polynesia, an overseas country of the F ...
: '' Pahi'', ''
tipairua Tipairua were large traditional sailing canoes of Tahiti that were of stately bearing and significance. They were often used for deep sea voyages, had low heads, high upturned stern The stern is the back or aft-most part of a ship or boat, te ...
''


Western development of sailing catamarans

Nathaniel Herreshoff's long catamaran, ''Duplex'', on the River Thames—built in 1877 The first documented example of double-hulled sailing craft in
Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
was designed by
William Petty Sir William Petty FRS (26 May 1623 – 16 December 1687) was an English economist, physician, scientist and philosopher. He first became prominent serving Oliver Cromwell and the Commonwealth in Ireland. He developed efficient methods to s ...
in 1662 to sail faster, in shallower waters, in lighter wind, and with fewer crew than other vessels of the time. However, the unusual design met with skepticism and was not a commercial success. The design remained relatively unused in the West for almost 160 years until the early 19th-century, when the Englishman Mayflower F. Crisp built a two-hulled merchant ship in Rangoon, Burma. The ship was christened ''Original''. Crisp described it as "a fast sailing fine sea boat; she traded during the monsoon between Rangoon and the Tenasserim Provinces for several years". Later that century, the American Nathanael Herreshoff constructed a double-hulled sailing boat of his own design (US Pat. No. 189,459). The craft, ''Amaryllis'', raced at her maiden regatta on June 22, 1876, and performed exceedingly well. Her debut demonstrated the distinct performance advantages afforded to catamarans over the standard monohulls. It was as a result of this event, the Centennial Regatta of the New York Yacht Club, that catamarans were barred from regular sailing classes, and this remained the case until the 1970s. On June 6, 1882, three catamarans from the Southern Yacht Club of
New Orleans New Orleans ( , ,New Orleans
raced a 15 nm course on
Lake Pontchartrain Lake Pontchartrain ( ) is an estuary located in southeastern Louisiana in the United States. It covers an area of with an average depth of . Some shipping channels are kept deeper through dredging. It is roughly oval in shape, about from w ...
and the winning boat in the catamaran class, ''Nip and Tuck'', beat the fastest sloop's time by over five minutes. In 1936,
Eric de Bisschop The given name Eric, Erich, Erikk, Erik, Erick, or Eirik is derived from the Old Norse name ''Eiríkr'' (or ''Eríkr'' in Old East Norse due to monophthongization). The first element, ''ei-'' may be derived from the older Proto-Norse languag ...
built a Polynesian "double canoe" in
Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
and sailed it home to a hero's welcome in France. In 1939, he published his experiences in a book, ''Kaimiloa'', which was translated into English in 1940.
Roland Roland (; frk, *Hrōþiland; lat-med, Hruodlandus or ''Rotholandus''; it, Orlando or ''Rolando''; died 15 August 778) was a Frankish military leader under Charlemagne who became one of the principal figures in the literary cycle known as the ...
and Francis Prout experimented with catamarans in 1949 and converted their 1935 boat factory in
Canvey Island Canvey Island is a town, civil parish and reclaimed island in the Thames estuary, near Southend-on-Sea, in the Castle Point district, in the county of Essex, England. It has an area of and a population of 38,170.Office for National Statistics ...
, Essex (England), to catamaran production in 1954. Their ''Shearwater'' catamarans easily won races against monohulls. ''Yellow Bird,'' a 1956-built '' Shearwater III'', raced successfully by Francis Prout in the 1960s, is in the collection of the National Maritime Museum Cornwall. Prout Catamarans, Ltd. designed a
mast aft rig A mast-aft rig is a sailboat sail-plan that uses a single mast set in the aft half of the hull. The mast supports fore-sails that may consist of a single jib, multiple staysails, or a crab claw sail. The mainsail is either small or completely abs ...
with the mast aft of midships to support an enlarged jib—more than twice the size of the design's reduced mainsail; it was produced as the ''Snowgoose'' model. The claimed advantage of this sail plan was to diminish any tendency for the bows of the vessel to dig in. upHobie 16 beachable catamaran In the mid-twentieth century,
beachcat A beachcat is an off-the-beach class of catamaran ("cat") sailboat. Background Although the term "beachcat" was popularized by surf board designer Hobie Alter, who designed the paradigm-changing Hobie 14 in 1965 and Hobie 16 in 1967, the under ...
s became a widespread category of sailing catamarans, owing to their ease of launching and mass production. In California, a maker of
surfboard A surfboard is a narrow plank used in surfing. Surfboards are relatively light, but are strong enough to support an individual standing on them while riding an ocean wave. They were invented in ancient Hawaii, where they were known as ''papa he'e ...
s,
Hobie Alter Hobart "Hobie" Alter (October 31, 1933 – March 29, 2014) was an American surf and sailing entrepreneur and pioneer, creator of the Hobie Cat catamarans, and founder of the Hobie company. Biography Hobie Alter will be remembered for creat ...
, produced the Hobie 14 in 1967, and two years later the larger and even more successful
Hobie 16 The ISAF International Class Hobie 16 (H16) is a popular catamaran manufactured by the Hobie Cat Company for racing and day sailing. The craft was the driving force behind the popularization of beachcats and was recently inducted into the Sai ...
. As of 2016, the Hobie 16 was still being produced with more than 100,000 having been manufactured. Catamarans were introduced to Olympic sailing in 1976. The two-handed Tornado catamaran was selected for the multihull discipline in the
Olympic Games The modern Olympic Games or Olympics (french: link=no, Jeux olympiques) are the leading international sporting events featuring summer and winter sports competitions in which thousands of athletes from around the world participate in a multi ...
from 1976 through 2008. It was redesigned in 2000. The
foiling A sailing hydrofoil, hydrofoil sailboat, or hydrosail is a sailboat with wing-like foils mounted under the hull. As the craft increases its speed the hydrofoils lift the hull up and out of the water, greatly reducing wetted area, resulting in de ...
Nacra 17 was used in the Tokyo 2020 Olympics, which were held in 2021; after the 2015 adoption of the Nacra 15 as a Youth World Championships class and as a new class for the Youth Olympic Games.


Performance

Catamarans have two distinct primary performance characteristics that distinguish them from displacement monohull vessels: lower resistance to passage through the water and greater stability (initial resistance to capsize). Choosing between a monohull and catamaran configuration includes considerations of carrying capacity, speed, and efficiency.


Resistance

At low to moderate speeds, a lightweight catamaran hull experiences resistance to passage through water that is approximately proportional to the square of its speed. A displacement monohull, by comparison, experiences resistance that is at least the cube of its speed. This means that a catamaran would require four times the power in order to double its speed, whereas a monohull would require eight times the power to double its speed, starting at a slow speed. For powered catamarans, this implies smaller power plants (although two are typically required). For sailing catamarans, low forward resistance allows the sails to derive power from attached flow, their most efficient mode—analogous to a wing—leading to the use of wingsails in racing craft.


Stability

Catamarans rely primarily on form stability to resist heeling and capsize. Comparison of heeling stability of a rectangular-cross section
monohull right A monohull is a type of boat having only one hull, unlike multihulled boats which can have two or more individual hulls connected to one another. Fundamental concept Among the earliest hulls were simple logs, but these were generally unsta ...
of beam, ''B'', compared with two catamaran hulls of width ''B''/2, separated by a distance, 2×''B'', determines that the catamaran has an initial resistance to heeling that is seven times that of the monohull. Compared with a monohull, a cruising catamaran sailboat has a high initial resistance to heeling and capsize—a fifty-footer requires four times the force to initiate a capsize than an equivalent monohull.


Tradeoffs

''Vangohh Seafarer'', a catamaran motor yacht berthed at Straits Quay, Georgetown, Pulau Pinang, Malaysia One measure of the trade-off between speed and carrying capacity is the displacement Froude number (FnV), compared with ''calm water transportation efficiency''. FnV applies when the
waterline length A vessel's length at the waterline (abbreviated to L.W.L)Note: originally Load Waterline Length is the length of a ship or boat at the level where it sits in the water (the ''waterline''). The LWL will be shorter than the length of the boat over ...
is too speed-dependent to be meaningful—as with a planing hull. It uses a reference length, the cubic root of the volumetric displacement of the hull, ''V'', where ''u'' is the relative flow velocity between the sea and ship, and ''g'' is acceleration due to gravity: :\mathrm = \frac ''Calm water transportation efficiency'' of a vessel is proportional to the full-load displacement and the maximum calm-water speed, divided by the corresponding power required. Large merchant vessels have a FnV between one and zero, whereas higher-performance powered catamarans may approach 2.5—denoting a ''higher speed'' per unit volume for ''catamarans''. Each type of vessel has a corresponding calm water transportation efficiency, with large transport ships being in the range of 100–1,000, compared with 11-18 for transport catamarans—denoting a ''higher efficiency'' per unit of payload for ''monohulls''.


SWATH and wave-piercing designs

A SWATH ship has twin hulls (blue) that remain completely submerged Two advances over the traditional catamaran are the '' small-waterplane-area twin hull'' (SWATH) and the ''wave-piercing'' configuration—the latter having become a widely favored design. SWATH reduces wave-generating resistance by moving displacement volume below the waterline, using a pair of tubular, submarine-like hulls, connected by pylons to the bridge deck with a narrow waterline cross-section. The submerged hulls are minimally affected by waves. The SWATH form was invented by Canadian Frederick G. Creed, who presented his idea in 1938 and was later awarded a British patent for it in 1946. It was first used in the 1960s and 1970s as an evolution of catamaran design for use as oceanographic research vessels or
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 ...
rescue ships. In 1990, the US Navy commissioned the construction of a SWATH ship to test the configuration. SWATH vessels compare with conventional powered catamarans of equivalent size, as follows: * Larger wetted surface, which causes higher skin friction drag * Significant reduction in wave-induced drag, with the configuration of struts and submerged hull structures * Lower water plane area significantly reduces pitching and heaving in a seaway * No possibility of planing * Higher sensitivity to loading, which may bring the bridge structure closer to the water HSV-2_Swift,_a_wave-piercing_trimaran,_built_by_Incat_in_Tasmania.html" ;"title="Incat.html" ;"title="HSV-2 Swift, a wave-piercing trimaran, built by Incat">HSV-2 Swift, a wave-piercing trimaran, built by Incat in Tasmania">Incat.html" ;"title="HSV-2 Swift, a wave-piercing trimaran, built by Incat">HSV-2 Swift, a wave-piercing trimaran, built by Incat in Tasmania, Australia Wave-piercing hull, Wave-piercing catamarans (strictly speaking they are
trimaran A trimaran (or double-outrigger) is a multihull boat that comprises a main hull and two smaller outrigger hulls (or "floats") which are attached to the main hull with lateral beams. Most modern trimarans are sailing yachts designed for recreatio ...
s, with a central hull and two outriggers) employ a low-buoyancy bow on each hull that is pointed at the water line and rises aft, up to a level, to allow each hull to pierce waves, rather than ride over them. This allows higher speeds through waves than for a conventional catamaran. They are distinguished from SWATH catamarans, in that the buoyant part of the hull is not tubular. The spanning bridge deck may be configured with some of the characteristics of a normal V-hull, which allows it to penetrate the crests of waves. Wave-piercing catamaran designs have been employed for yachts, passenger ferries, and military vessels.


Applications

upEmirates Team New Zealand's AC72 ''Aotearoa'' on foils in San Francisco Bay '' Tûranor PlanetSolar'', a wave-piercing solar-powered cruising trimaran in Hamburg, Germany A catamaran configuration fills a niche where speed and sea-kindliness is favored over bulk capacity. In larger vessels, this niche favors car ferries and military vessels for patrol or operation in the littoral zone.


Sport

left, Gitana 13, an ocean-racing catamaran Recreational and sport catamarans typically are designed to have a crew of two and be launched and landed from a beach. Most have a trampoline on the bridging structure, a rotating mast and full-length battens on the mainsail. Performance versions often have trapezes to allow the crew to hike out and counterbalance capsize forces during strong winds on certain points of sail. For the 33rd America's Cup, both the defender and the challenger built long multihulls.
Société Nautique de Genève The Société Nautique de Genève is a yacht club based in Geneva (Switzerland). It was founded in 1872 with the goal of developing nautical sports and high level sailors. Currently the club has about 3000 members. The club held the America's Cup ...
, defending with team
Alinghi Alinghi, or Alinghi Red Bull Racing because of the sports marketing branding by Red Bull, is the syndicate set up by Ernesto Bertarelli, racing under the colors of the Société Nautique de Genève, to challenge for the America's Cup, as well as ...
, sailed a catamaran. The challenger, BMW Oracle Racing, used a trimaran, replacing its soft sail rig with a towering
wing sail 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 ...
—the largest sailing wing ever built. In the waters off
Valencia Valencia ( va, València) is the capital of the autonomous community of Valencia and the third-most populated municipality in Spain, with 791,413 inhabitants. It is also the capital of the province of the same name. The wider urban area al ...
, Spain in February 2010, the BMW Oracle Racing trimaran with its powerful wing sail proved to be superior. This represented a break from the traditional monohulls that had always been sailed in previous
America's Cup The America's Cup, informally known as the Auld Mug, is a trophy awarded in the sport of sailing. It is the oldest international competition still operating in any sport. America's Cup match races are held between two sailing yachts: one ...
series. On San Francisco Bay, the 2013 America's Cup was sailed in long AC72 catamarans (craft set by the rules for the 2013 America's Cup). Each yacht employed
hydrofoil A hydrofoil is a lifting surface, or foil, that operates in water. They are similar in appearance and purpose to aerofoils used by aeroplanes. Boats that use hydrofoil technology are also simply termed hydrofoils. As a hydrofoil craft gains s ...
s and a wing sail. The regatta was won 9-8 by
Oracle Team USA Oracle Team USA is an American yacht racing syndicate initially formed to compete for the 2003 America's Cup. They competed again in the 2007 event before winning the 33rd America's Cup regatta in 2010 – representing the Golden Gate Yacht Clu ...
against the challenger,
Emirates Team New Zealand Team New Zealand or TNZ is a sailing team based in Auckland, New Zealand representing the Royal New Zealand Yacht Squadron. Team New Zealand became a household name in their home country following their consecutive wins in the America's Cup ...
, in fifteen matches because Oracle Team USA had started the regatta with a two-point penalty. Yachting has seen the development of multihulls over in length. " The Race" helped precipitate this trend; it was a circumnavigation challenge which departed from Barcelona, Spain, on New Year's Eve, 2000. Because of the prize money and prestige associated with this event, four new catamarans (and two highly modified ones) over in length were built to compete. The largest, ''
PlayStation is a video gaming brand that consists of five home video game consoles, two handhelds, a media center, and a smartphone, as well as an online service and multiple magazines. The brand is produced by Sony Interactive Entertainment, a di ...
'', owned by
Steve Fossett James Stephen Fossett (April 22, 1944 – September 3, 2007) was an American businessman and a record-setting aviator, sailor, and adventurer. He was the first person to fly solo nonstop around the world in a balloon and in a fixed-wing aircraf ...
, was long and had a mast which was above the water. Virtually all of the new mega-cats were built of pre-preg
carbon fiber Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...
for strength and the lowest possible weight. The top speeds of these boats can approach . The Race was won by the -long catamaran ''
Club Med Club Med SAS, commonly known as Club Med and previously known as Club Méditerranée SA, is a French travel and tourism operator headquartered in Paris, specializing in all-inclusive holidays. Founded in 1950, the company has been primarily o ...
'' skippered by
Grant Dalton Grant Stanley Dalton (born 1 July 1957) is a New Zealand sailor who has competed in five Whitbread Round the World Races and currently manages Team New Zealand. Background Dalton is a professional sailor who started sailing at the age 8 in th ...
. It went round the globe in 62 days at an average speed of . Catamarans for whitewater sports. Picture was taken in Altai, Russia Whitewater catamaran—sometimes called "cata-rafts"—for whitewater sports are widely spread in
post-Soviet countries The post-Soviet states, also known as the former Soviet Union (FSU), the former Soviet Republics and in Russia as the near abroad (russian: links=no, ближнее зарубежье, blizhneye zarubezhye), are the 15 sovereign states that wer ...
. They consists of two inflatable hulls connected with a lattice scaffold. The frame of the tourist catamaran can be made of both aluminum (duralumin) pipes and from felled tree trunks. The inflatable part has two layers—an airtight balloon with inflation holes and a shell made of dense tissue, protecting the balloon from mechanical damage. Advantages of such catamarans are light weight, compactness and convenience in transportation (the whole product is packed in one pack-backpack, suitable for air traffic standards) and the speed of assembly (10–15 minutes for the inflation). All-inflatable models are available in North America. A cata-raft design has been used on the Colorado River to handle heavy whitewater, yet maintain a good speed through the water.


Cruising

left, A cruising catamaran Cruising sailors must make trade-offs among volume, useful load, speed, and cost in choosing a boat. Choosing a catamaran offers increased speed at the expense of reduced load per unit of cost. Howard and Doane describe the following tradeoffs between cruising monohulls and catamarans: A long-distance, offshore cruising monohull may be as short as for a given crew complement and supporting supplies, whereas a cruising catamaran would need to be to achieve the same capacity. In addition to greater speed, catamarans draw less water than do monohulls— as little as —and are easier to beach. Catamarans are harder to tack and take up more space in a marina. Cruising catamarans entail added expense for having two engines and two rudders. Tarjan adds that cruising catamarans boats can maintain a comfortable per day passage, with the racing versions recording well over per day. In addition, they do not heel more than 10-12 degrees, even at full speed on a reach. Powered cruising catamarans share many of the amenities found in a sail cruising catamaran. The saloon typically spans two hulls wherein are found the staterooms and engine compartments. As with sailing catamarans, this configuration minimizes boat motion in a seaway. The Swiss-registered wave-piercing catamaran, '' Tûranor PlanetSolar'', which was launched in March 2010, is the world's largest
solar powered Solar energy is radiant light and heat from the Sun that is harnessed using a range of technologies such as solar power to generate electricity, solar thermal energy (including solar water heating), and solar architecture. It is an essen ...
boat. It completed a
circumnavigation Circumnavigation is the complete navigation around an entire island, continent, or astronomical body (e.g. a planet or moon). This article focuses on the circumnavigation of Earth. The first recorded circumnavigation of the Earth was the ...
of the globe in 2012.


Passenger transport

The 1970s saw the introduction of catamarans as high-speed ferries, as pioneered by Westermoen Hydrofoil in
Mandal A tehsil (, also known as tahsil, taluka, or taluk) is a local unit of administrative division in some countries of South Asia. It is a subdistrict of the area within a district including the designated populated place that serves as its administr ...
, Norway, which launched the
Westamaran The Westamaran is a pioneer type of passenger transport high speed catamarans developed by Westermoen Hydrofoil in 1973. The craft was highly successful, and introduced a new era of passenger transport along the Norwegian coast and elsewhere. O ...
design in 1973. The '' Stena Voyager'' was an example of a large, fast ferry, typically traveling at a speed of , although it was capable of over . The Australian island
Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...
became the site of builders of large transport catamarans—
Incat Incat Tasmania is an Australian manufacturer of high-speed craft (HSC) catamaran ferries. Its greatest success has been with large, sea going passenger and vehicle ferries, but it has also built military transports and since 2015 it has built s ...
in 1977 and
Austal Austal is an Australian-based global ship building company and defence prime contractor that specialises in the design, construction and support of defence and commercial vessels. Austal's product range includes naval vessels, high-speed passeng ...
in 1988—each building civilian ferries and
naval 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 inclu ...
vessels. Incat built HSC Francisco, a High-Speed trimaran that, at 58 knots, is (as of 2014) the fastest
passenger ship A passenger ship is a merchant ship whose primary function is to carry passengers on the sea. The category does not include cargo vessels which have accommodations for limited numbers of passengers, such as the ubiquitous twelve-passenger freig ...
in service.


Military

US Naval Ship ''Spearhead'' (JHSV-1) during sea trials in 2012 The first warship to be propelled by a steam engine, named ''Demologos'' or ''Fulton'' and built in the United States 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 be ...
, was a catamaran with a
paddle wheel A paddle wheel is a form of waterwheel or impeller in which a number of paddles are set around the periphery of the wheel. It has several uses, of which some are: * Very low-lift water pumping, such as flooding paddy fields at no more than a ...
between her hulls. In the early 20th Century several catamarans were built as submarine salvage ships: SMS ''Vulkan'' and SMS ''Cyclop'' of
Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...
, ''Kommuna'' of
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-ei ...
, and ''Kanguro'' of
Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...
, all designed to lift stricken
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 ...
s by means of huge cranes above a
moon pool A moon pool is a feature of marine drilling platforms, drillships and diving support vessels, some marine research and underwater exploration or research vessels, and underwater habitats, in which it is also known as a wet porch. It is an o ...
between the hulls. Two Cold War-era
submarine rescue ship A submarine rescue ship is a surface support ship for submarine rescue and deep-sea salvage operations. Methods employed include the McCann Rescue Chamber, deep-submergence rescue vehicles (DSRV's) and diving operations. List of active su ...
s, USS ''Pigeon'' and USS ''Ortolan'' of the
US Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...
, were also catamarans, but did not have the moon pool feature. The use of catamarans as high-speed naval transport was pioneered by HMAS ''Jervis Bay'', which was in service with the
Royal Australian Navy The Royal Australian Navy (RAN) is the principal naval force of the Australian Defence Force (ADF). The professional head of the RAN is Chief of Navy (CN) Vice Admiral Mark Hammond AM, RAN. CN is also jointly responsible to the Minister o ...
between 1999 and 2001. The US
Military Sealift Command Military Sealift Command (MSC) is an organization that controls the replenishment and military transport ships of the United States Navy. Military Sealift Command has the responsibility for providing sealift and ocean transportation for all US ...
now operates several Expeditionary Fast Transport catamarans owned by the US Navy; they are used for high speed transport of military cargo, and to get into shallow ports. The ''Makar''-class is a class of two large catamaran-hull survey ships built for the
Indian Navy The Indian Navy is the maritime branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy. The Chief of Naval Staff, a four-star admiral, commands the navy. As a blue-water navy, it operates si ...
. As of 2012, one vessel, INS Makar (J31), was in service and the second was under construction. First launched in 2004 at Shanghai, the Houbei class missile boat of the
People's Liberation Army Navy The People's Liberation Army Navy (PLAN; ), also known as the People's Navy, Chinese Navy, or PLA Navy, is the maritime service branch of the People's Liberation Army. The PLAN traces its lineage to naval units fighting during the Chines ...
(PLAN) has a catamaran design to accommodate the vessel's stealth features.


See also

*
List of multihulls Types * catamaran = two symmetric hulls * proa = two asymmetric hulls, reverse-shunting (interchangeable bow/ stern) * trimaran = three hulls * quadrimaran = four hulls * pentamaran = five hulls Pre-modern Austronesian * ʻalia * Amatasi * B ...


References


Further reading

* {{Authority control Naval architecture Shipbuilding * Multihulls Nautical terminology Austronesian culture