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The Salem Ferry Catamaran approaching its dock off Blaney Street in Salem, Massachusetts, USA.
A traditional "kattumaram" at Pulicat Lake in South India
Two catamaran sailboats, leaving Saint-Vaast Harbour


A catamaran is geometry-stabilized, that is, it derives its stability from its wide beam, rather than having a ballasted keel like a monohull. Being ballast-free and lighter than a monohull, a catamaran can have a very shallow draught. The two hulls will be much finer than a monohull's, the reduced drag allowing faster speeds. A sailing multihull will heel much less than a sailing monohull, so its sails spill less wind and are more efficient. The limited heeling means the ride may be more comfortable for passengers and crew, although catamarans can exhibit an unsettling "hobby-horse" motion. Unlike a self-righting monohull, if a gust causes a sailing catamaran to capsize, it may be impossible to right the multihull; but having no ballast, an upturned catamaran will be unlikely to sink.

A catamaran's two hulls are joined by some structure, the most basic being a frame, formed of akas. More sophisticated catamarans combine accommodation into the bridging superstructure. Catamarans may be driven by sail and/or engine. Originally catamarans were small yachts, but now some ships and ferries have adopted this hull layout because it allows increased speed, stability and comfort.

The catamaran concept is a relative newcomer for Western boat designers, although they have been used since time immemorial among the Dravidian people, in South India. Catamarans were developed independently[citation needed] in Oceania, where Polynesian catamarans and outrigger canoes allowed seafaring Polynesians to voyage to the remotest Pacific islands.

In recreational sailing, catamarans and trimarans initially met some skepticism from Western sailors versed in traditional ballasted monohull designs.[1]

Multihull component terms[edit]

The word catamaran is derived from the Tamil word kaṭṭumaram (கட்டுமரம்), literally "tied wood" (from kaṭṭu "to tie" and maram "wood, tree").[2][3][4] A "kattumaram", a geometry-stabilized rowboat used by the Tamil people, shares component part-names with the proa, a multihull sailboat used by the Oceanic people. Although the original "kattumaram" included a monohull raft, the modern word catamaran exclusively means a twin-hulled vessel.

In the United States, there are three terms that describe the main components of catamarans and trimarans, namely: “vaka”, “aka”, and “ama”,[5] terms derived from the Malay and Micronesian language group terms for parts of the outrigger canoe. These terms, which reflects only American usage, are unknown in the UK, where simple English words are used instead.

In Hawaiian, the main difference is the main hull or canoe is a wa'a pronounced like va ah. There is no plural in Hawaiian and so a double canoe, or two canoes joined together by aka is a wa'a wa'a. An area in lower Puna is called wa'a wa'a. A comprehensive list of Hawaiian words for a boat is published by the Polynesian Voyaging Society.[7]


Polynesian cats[edit]

A Polynesian catamaran

While the English adventurer and buccaneer William Dampier was traveling around the world in search of business opportunities, he found himself on the south-western coast of India. He was the first to write in English about a kind of vessel he observed there. It was little more than a raft made of logs.


The vessels described by Dampier are still in use today on the coasts of South India. "kattumaram" literally means logs tied together. Today's kattumarams have about four logs tied together in a shallow arc to make a raft. The logs are usually from a local, fibrous palm tree. Typically the raft is untied and logs are scattered to dry out before reuse.

Although the name came from Tamil, the one-hull-ballasted sailboat variant is from South Pacific. English visitors applied the Tamil name catamaran to the swift, stable sail and paddle boats made out of two widely separated logs and used by Polynesian natives to get from one island to another.

Older European cats[edit]

The larger Hellenistic polyremes ("sixteens", "twenties", "thirties" and one "forty") were most likely double-hulled catamarans.[8] Two such super-galleys built by the Ptolemaic king Ptolemy IV (221–205 BC) have come down to us by name, the Thalamegos and the Tessarakonteres. Catamarans were also used by Greeks engineers under Ptolemy II (283–246 BC) as obelisk carriers:

It was conveyed by Phoenix, who by digging a canal brought the waters of the Nile right up to the place where the obelisk lay. Two very broad ships were loaded with cubes of the same granite as that of the obelisk, each cube measuring one foot, until calculations showed that the total weight of the blocks was double that of the obelisk, since their total cubic capacity was twice as great. In this way, the ships were able to come beneath the obelisk, which was suspended by its ends from both banks of the canal. Then the blocks were unloaded and the ships, riding high, took the weight of the obelisk. (Pliny, Nat. Hist. 36; 14, 67–68)

Early modern cats[edit]

A present sweep row training on catamaran

Early modern Europe's first documented catamaran was designed by the polymath and Royal Society member William Petty in 1662. It was designed to sail faster, in shallower waters, with less wind & crew than other vessels of the time, but the unusual design met with scepticism and was not a commercial success.[9][10] The design remained relatively unknown in the West for almost another 160 years when in the 1820s or 1830s an Englishman called May Flower Crisp built a two-hulled merchant ship called "Original" at Rangoon in Burma (modern Myanmar) and described it as "a fast sailing fine sea boat; she traded during the monsoon between Rangoon and the Tenasserim Provinces for several years".[11] Later, an American, Nathanael Herreshoff, began to build catamaran boats of his own design in 1877 (US Pat. No. 189,459), namely 'Amaryllis', which immediately showed her superior performance capabilities, at her maiden regatta (The Centennial Regatta held on June 22, 1876, off the New York Yacht Club's Staten Island station[1]). It was this same event, after being protested by the losers, where catamarans, as a design, were barred from all the regular classes[1] and they remained barred until the 1970s.

This ban relegated the catamaran to being a mere novelty boat design for many years.[12]

In 1936 Eric de Bisschop built a Polynesian "double canoe" in Hawaii and sailed it home to a hero's welcome in France. In 1939, he published his book Kaimiloa, which was translated in English in 1940.

In 1947, surfing legend, Woodbridge "Woody" Brown and Alfred Kumalae designed and built the first modern ocean-going catamaran, Manu Kai, in Hawaii. Their young assistant was Rudy Choy, who later founded the design firm Choy/Seaman/Kumalae (C/S/K, 1957) and became a fountainhead for the catamaran movement. The Prout Brothers, Roland and Francis, experimented with catamarans in 1949 and converted their 1935 boat factory in Canvey Island, Essex (England), to catamaran production in 1954. Their Shearwater catamarans won races easily against the monohulls. Yellow Bird a 1953-built Shearwater, raced successfully by Francis Prout in the 1960s, is in the collection of the National Maritime Museum Cornwall. Inspired by de Bisshop's Kamiloa, in 1955 James Wharram built a utilitarian catamaran and sailed across the Atlantic with a crew of two German girls. In Trinidad he built another one and returned via the North Atlantic, west to east, pioneering catamaran cruising (maritime). James Wharram designs are a reference for simple, not too expensive self-built boats. Not needing a keel catamarans are more suitable for DIY construction.[13]

A Hobie catamaran sailboat


In 1970 Les Thompson began work in Inverloch, Australia, to single-handedly build the Llinase, a 70-tonne, 24 meter steel ketch motor-sailer which was subsequently launched in 1980. The vessel was able to "walk" up any suitable beach using a shunting system located under the wing and powered by hydraulic rams.

Sailing and transport[edit]

Maxi Catamaran Orange II

In the mid-twentieth century, the catamaran inspired an even more popular sailboat, the Beach Cat. In California, a maker of surfboards, Hobie Alter produced the 250-pound in 1967, and two years later the larger and even more successful Hobie 16. That boat remains in production, with more than 100,000 made in the past three decades.
The Tornado catamaran was an Olympic class sailing catamaran since 1976, with a crew of two. It was designed in 1967 by Rodney March of Brightlingsea, England, with help from Terry Pierce, and Reg White, specifically for the purpose of becoming the Olympic catamaran. At the IYRU Olympic Catamaran Trials, it easily defeated the other challengers.

Important builders of transport catamarans are Austal and Incat, both of Australia and best known for building large catamarans both as civilian ferries and as naval vessels.

Usage and application[edit]

Faster boats[edit]

Catamarans, specifically the multi-hulls, are normally faster than single-hull boats for two reasons : less drag, more power.


An example of an off the beach catamaran is the Ron Given of New Zealand designed Paper Tiger Catamaran

Catamarans' peculiarities[edit]



Catamaran sailing[edit]

A small Formula 16 sailing catamaran


Lagoon 380 showing her keels


Cruising sail cats[edit]

Below a minimum size, about 8 m (24 ft), the catamaran's hulls do not have enough volume to allow them to be used as living space. At the same time, the bridgedeck area isn't sufficiently sized to make effective live-aboard space either.


While more popular in Europe and Australia, they are gaining popularity in the US as well.[citation needed] These boats can maintain a comfortable 300 nmpd (nautical miles per day) passage, with the racing versions recording well over 400 nmpd.[citation needed] In addition, they don't heel more than 10-12 degrees, even at full speed on a reach.[citation needed]






Powered catamarans[edit]

Cruising powered cats[edit]




The Swiss-registered catamaran Tûranor PlanetSolar which was launched in March 2010, is the world's largests solar powered boat and has completed the circumnavigation of the globe in 2012.

Passenger transport[edit]


An increasing trend is the deployment of a catamaran as a high-speed ferry. The use of catamaran for high-speed passenger transport was pioneered by Westermoen Hydrofoil in Mandal, Norway, who launched the Westamaran design in 1973. The Westamarans, and later designs, some of them consisting of a catamaran hull resting on an air cushion between the hulls, became dominant for all high-speed connections along the Norwegian coast. They could achieve speeds comparable to the hydrofoils that it replaced, and was much more tolerant of foul water and wave conditions.

Since the 1970s, the length of catamarans increased from some 20 m up to 115 m long.[16] The high-speed Stena (HSS) is the world's largest fast ferry, traveling at a speed of 46 mph, although it is capable of doing over 70 mph.


Military cats[edit]

HSV-X1 Joint Venture, a large, experimental, high-speed military catamaran.

A military catamaran is being designed for the U.S. Navy and is in its experimental phase. It is much more resilient and faster than ordinary catamarans.

The Alcock Ashdown Class is a class of 6 large catamaran hull survey ships being built for the Indian Navy. One ship INS Makar (J31) is in service from 2012 and 5 more under various stages of construction.

INS Makar, a large survey catamaran of the Indian Navy.


Basic Catamaran

Two main types of catamaran exist: the regular catamaran and the open catamaran, which features a trampoline between the hulls instead of plating. The normal catamaran multihull, powered or not, consists of two Amas separated by two Akas, which may suspend a platform or trampoline between them. They can be of various sizes and, recently, have become very large.


SWATH type


Catamarans provide large, broad decks. It also allows for a design that greatly reduce water resistance (the part that generates waves) by moving as much displacement volume as possible to the lower hull and narrowing the waterline cross-section sharply, creating the distinctive pair of bulbous hulls below the waterline and the narrow struts supporting the upper hull. This design means that the ship's flotation runs mostly under the waves, like a submarine (the smooth ride of a sub was the inspiration for the design). The result is that a fairly small ship can run very steadily in rough seas. A 50-meter ship can operate at near full power in nearly any direction in waves as high as 12 meters.[citation needed]


Pontoon Boat 
Hydroairy Ship 
SWATH pilot boat in Rotterdam 
Another Dutch SWATH Pilot boat 
Research ship Planet of the German Navy 

Pontoon boat or hydroairy ship[edit]

Hydroairy or Pontoon type




An unconventional design is the MAR Proteus.[18]

catamaran in Lake Constance 
TurboJET's Barca Foilcat 

Catamaran kits[edit]

One factor following the rise of popularity in catamarans is the popularity of catamaran "kits". Most popular are materials such as woven fibreglass fabrics and foam, balsa or paper-honeycomb cores. These materials are pressed to create "panels" which are then often cut to specific shapes and parts for construction by amateurs or professionals.

See also[edit]


  1. ^ a b c L. Francis Herreshoff. "The Spirit of the Times, November 24, 1877 (reprint)". Marine Publishing Co., Camden, Maine. Archived from the original on 2008-01-24. 
  2. ^ "Catamaran". Retrieved 2012-06-06. 
  3. ^ Farlex. "Catamaran". Retrieved 2012-06-06. 
  4. ^ Thompson, Della (1998). The Concise Oxford Dictionary (9th ed.). Oxford University Press. p. 205. ISBN 0198613202. 
  5. ^ "The Tridarka Raider". Retrieved 2007-10-30. 
  6. ^ a b c "A Primer on Proas". Archived from the original on 2007-10-08. Retrieved 2007-10-30. 
  7. ^ "Polynesian Voyaging Society". 
  8. ^ Lionel Casson (1969): "The Super-Galleys of the Hellenistic Age", Mariner's Mirror, Vol. 55, pp. 185-193
  9. ^
  10. ^
  11. ^ B R Pearn "A History of Rangoon", Corporation of Rangoon 1938 page 136; M F Crisp "A Treatise on Marine Architecture" Maulmein 1849 p94
  12. ^ The UCI later created this same sort of ban, in 1934, when it invalidated Faure's record of 45km in one hour, in 7 July 1933, on a Recumbent bicycle, with rule changes specifically designed to exclude the recumbent bicycle, where Recumbent bicycle technology was similarly repressed.
  13. ^ Harvey, Dereck, Multihulls for Cruising and Racing, Adlard Coles, London 1990 p. 16, ISBN 0-07136-6414-2
  14. ^ "Frequently Asked Questions on Multihulls". 
  15. ^ Jim Howard, Charles J. Doane. Handbook of offshore cruising: The Dream and Reality of Modern Ocean Cruising. Sheridan House, Inc. p. 280. ISBN 1-57409-093-3. 
  16. ^ InCat, one of the largest wave-piercing catamaran builders
  17. ^ Weeres History - "An Idea that Started an Industry"
  18. ^ WAMV Proteurs images


External links[edit]