tri- + maran

A trimaran is a vessel with three hulls: one central and two outriggers. The word is a 20th-century coinage: tri- (Greek: three) plus maran, from the Tamil word kattumaram — 'tied wood' or 'bound timber.' Catamarans (two hulls, from Tamil kattu: to tie, maram: wood) have been sailed by Tamil fishermen off the Coromandel Coast for at least two thousand years. The trimaran extends this logic to three hulls.

The multi-hull design achieves stability through width rather than weight. A monohull (single-hulled vessel) stays upright by having a heavy keel low in the water; remove the keel and the boat heels dangerously. A trimaran achieves stability because if one hull lifts, the other two resist. This means trimarans can be extremely light — and light means fast. The current record for sailing around the world is held by a trimaran.

Victor Tchetchet, a Russian émigré to the United States, built the first modern trimaran in 1945, inspired by his study of Polynesian proa designs. Arthur Piver popularized trimarans in the 1960s with plans that amateur builders could use. By the 1970s, offshore trimarans were winning races. By the 1990s, Jules Verne Trophy attempts (circumnavigation) were dominated by the design.

The Tamil fishermen on the Coromandel Coast who tied logs together centuries ago would not recognize a modern race trimaran — a carbon fiber structure fifty meters long weighing thirty tons less than its monohull equivalent. But the principle is unchanged. Three floating bodies, tied together, moving faster than any single hull could manage.