Catamaran

A catamaran (/ˌkætəməˈræn/) (informally, a “cat”) is a multi-hulled watercraft 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 as with a monohull boat. Catamarans typically have less hull volume, smaller displacement, and shallower draft (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 which enabled their expansion to the islands of the Indian and Pacific Oceans.

Catamarans range in size from small sailing or rowing vessels to large naval ships and roll-on/roll-off 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 and Maritime Southeast Asia 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 (கட்டுமரம்), which means “logs bound together”. However, the original kattumaram did not refer to double-hulled boats at all, but to a type of single-hulled raft made of three to seven tree trunks lashed together. The term has evolved in English usage to refer solely to unrelated double-hulled boats.

Development in Oceania and Asia

Catamaran-type vessels were an early technology of the Austronesian peoples. Early researchers like Heine-Geldern (1932) and Hornell (1943) once believed that catamarans evolved from outrigger canoes, but modern authors specializing in Austronesian cultures like Doran (1981) and Mahdi (1988) now believe it to be the opposite.

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, 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 trimarans).

This would also explain why older Austronesian populations in Island Southeast Asia 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, Madagascar, and the Comoros, 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). To deal with the problem of the instability of the boat when the outrigger faces leeward when tacking, they instead developed the shunting 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:

• Fiji: Drua (or Wangga tabu)
• Papua New Guinea: Lakatoi
• Tonga: Hamatafua, Kalia, Tongiaki

• Polynesia

• Cook Islands: Vaka katea
• Hawaii: Waʻa kaulua
• Marquesas: Vaka touʻua
• New Zealand: Waka hourua
• Samoa: ʻAlia, Amatasi, Va’a-tele
• Society Islands: Pahi, Tipairua

Western development of sailing catamarans

The first documented example of double-hulled sailing craft in Europe was designed by William Petty 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 raced a 15 nm course on Lake Pontchartrain 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 built a Polynesian “double canoe” in Hawaii 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 and Francis Prout experimented with catamarans in 1949 and converted their 1935 boat factory in Canvey Island, 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 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.