catamaran

catamaran, from the Tamil katta, to tie, maram, wood.

1. A sort of raft consisting of two or more logs or tree trunks lashed together and used as a surf boat in the East and West Indies. The term was also used to describe the much larger rafts, made normally from the trunks of balsa trees, which used to be seen on the western coast of South America.

2. A raft used in the St Lawrence River, made by lashing two boats together.

3. A British naval explosive invention which was specially designed to attack the French invasion flotilla as it lay in harbour at Boulogne in the autumn of 1804.

4. A small rectangular raft used in dockyards to protect the hulls of large ships from damage when lying alongside a mole or jetty.

5. A twin-hulled vessel, present in the Pacific and Indian Oceans for hundreds of years, although its appearance in European and North American waters was much later. The first steam propulsion warship, designed by Robert Fulton in 1814, had two hulls and in 1874 the London, Chatham, and Dover Railway built a twin-hulled ferry of 1,533 tons for their cross-Channel service. During the 1990s a cross-Channel ferry company started using twin-hulled Seacats, wave-piercing designs where the hulls were designed to slice through the waves instead of over them, and they are now in use throughout the world. Similar designs are being used for military purposes by the Royal Australian and US Navies. The Royal Navy is also experimenting with a twin-hulled warship, and the UK's first purpose-built floating ambulance, Star of Life, is a catamaran. See also surface effect ship; swath ship.

The catamaran is very popular for recreational sailing, as it is both stable and fast, though a catamaran cannot sail as close to the wind as a monohull. One of the earliest, if not the earliest, sailing catamarans to be built for racing was designed by Nat Herreshoff, the American yacht designer, in 1876, and one was used successfully to defend the America's Cup in 1988. Wave-piercing catamarans have also been developed for ocean racing. See also canoe; trimaran; yachting: transoceanic racing.