Catamaran

A catamaran is a twin-hulled watercraft characterised by two parallel hulls of equal size connected by a frame or superstructure. This configuration gives the vessel inherent stability, minimal heeling and reduced hydrodynamic drag compared with monohulls of similar length. Catamarans range from small recreational sailing craft to large motorised ferries and naval vessels, and can be designed for rowing, sailing or powered propulsion. Their shallow draught, high speed potential and efficient performance have made them widely used in leisure, transport and long-distance voyaging.

Etymology

The term catamaran derives from the Tamil kattumaram, meaning “logs bound together”. In its original context the word referred to a raft constructed of several lashed tree trunks rather than a twin-hulled craft. Through European adoption the term gradually shifted and became applied to the distinct double-hulled vessels familiar today.

Austronesian development and traditional forms

Catamarans originated among the Austronesian peoples, whose maritime cultures in Island Southeast Asia and the Pacific pioneered the use of multihull craft. Early Austronesian vessels included two-log rafts from which the twin-hulled canoe form developed. Unlike earlier theories suggesting that catamarans evolved from outrigger canoes, more recent scholarship argues the reverse: double canoes preceded outriggers.
Over time, symmetric double canoes evolved into asymmetric variants in which one hull was smaller. This smaller hull then became the basis for the outrigger, giving rise to single and, later, double outriggers. These forms spread through western Melanesia and Island Southeast Asia, while more distant Austronesian-descended populations in Madagascar, the Comoros and much of Oceania retained the twin-hulled and single-outrigger forms.
In regions where double outriggers did not develop, navigators compensated for sailing instability using the shunting technique, which reverses the boat’s forward direction when tacking leeward. This innovation is a hallmark of Micronesian and Polynesian seamanship.
Examples of traditional Austronesian catamarans include:

• Drua or waqa tabu
• Lakatoi
• Hamatafua
• Kalia and tongiaki
• Vaka katea and waa kaulua
• Vaka touua
• Waka hourua
• Alia, amatasi and vaʻa tele
• Pahi and tipairua

These vessels enabled extensive voyaging across the Indian and Pacific Oceans and were central to the expansion, trade networks and cultural integration of Austronesian societies.

Early Western interest and modern development

European experimentation with double-hulled designs began in the seventeenth century, when William Petty produced a twin-hulled sailing craft in 1662 intended to combine speed, shallow draught and reduced crew requirements. Although technically innovative, it gained little acceptance.
Further progress occurred in the nineteenth century. Mayflower F. Crisp constructed a catamaran-type merchant vessel in Yangon, praised for its seaworthiness during monsoon trading. Around the same period, American designer Nathanael Herreshoff patented a twin-hulled sailing craft. His vessel Amaryllis achieved notable racing success in 1876, leading to a temporary ban of catamarans from New York Yacht Club sailing classes due to their superior performance.
By the late nineteenth century, catamarans such as Nip and Tuck demonstrated clear speed advantages over monohulls in organised regattas. In 1916 Leonardo Torres Quevedo patented his “Binave Twin Ship”, a steel catamaran with adjustable rudders and twin marine engines—an early example of powered multihull engineering.
The twentieth century saw renewed interest in multihulls. Eric de Bisschop’s 1936 Polynesian double canoe voyage brought global attention to traditional designs. The post-war era witnessed decisive expansion in Western sailing catamarans, driven by designers Roland and Frank Prout, whose Shearwater models achieved racing success and influenced production techniques. Prout’s later Snowgoose design introduced a mast-aft rig intended to reduce bow-digging.
The 1960s and 1970s marked the rise of “beach cats”, lightweight sailing catamarans that could be easily launched from shore. Hobie Alter’s Hobie 14 (1967) and Hobie 16 (1969) were particularly influential and widely manufactured. Catamarans entered Olympic sailing in 1976 with the Tornado class and continued evolving with the hydrofoiling Nacra 17 used in the Tokyo 2020 Games.

Performance characteristics

Catamarans exhibit several performance advantages over monohulls, chiefly in stability and resistance:

• Stability: Their wide beam provides strong initial resistance to rolling and capsize without requiring ballast. This gives a smoother ride and reduced heeling, particularly in sailing craft.
• Resistance and drag: At low to moderate speeds, lightweight catamaran hulls experience resistance roughly proportional to speed, similar to displacement monohulls. However, because each hull is narrow, surface friction and wave-making resistance are reduced. As speed increases, resistance depends on hull length, displacement-to-length ratio and hull spacing. The resulting resistance profile contains small peaks as interacting wave trains reinforce or cancel one another.
• Propulsion efficiency: Smaller engines can often be used for powered catamarans, though two power plants are typically required. Sailing catamarans benefit from enhanced aerodynamic leverage because the separation of hulls allows sails to generate effective lateral forces with minimal heeling.

The configuration offers speed advantages, fuel efficiency and reduced wake production, making catamarans well suited for high-speed ferries, recreational sailing and coastal patrol vessels.

Structural forms and modern applications

The structure connecting a catamaran’s hulls varies widely:

• Simple frames with webbing for lightweight sport catamarans
• Bridging superstructures incorporating cabins, decks and cargo space for cruising and commercial vessels
• High-capacity platforms for roll-on/roll-off ferries and naval craft