trimaranes

A trimaran is a type of multihull boat with three parallel hulls: a main hull and two smaller outrigger hulls called amas. The amas are connected to the main hull by struts, producing a very wide beam. This arrangement gives high stability at rest and in light winds, while allowing shallow draft compared with a single-hulled vessel. Under sail, trimarans can attain high speeds through reduced hull resistance and efficient planing.

Origins and use: The concept traces to traditional Polynesian outrigger canoes. In the 20th century, trimarans were developed for cruising and racing, and are now common in both sailing yachts and power-assisted craft. Some designs emphasize speed, others emphasize comfort for long passages. Many cruising models use folding or retractable amas to reduce beam for transport and storage.

Design features: The main hull carries the rig and accommodations, while the amas provide stability and buoyancy. Rig options range from single-mast to multi-mast configurations. Modern trimarans use lightweight materials such as fiberglass, epoxy, and carbon fiber. Some models are built with water ballast, modular construction, or removable amas to adapt to conditions.

Performance and handling: Trimarans offer high initial stability, good resistance to rolling, and strong potential speeds, especially when planing. They typically have shallow drafts and broad living spaces for their size. Disadvantages include higher build and maintenance costs, more complex rigging, and potential handling challenges in heavy seas or at low speeds when stability is reduced if a hull comes to water.

Overall, trimaranes represent a versatile family in modern sailing, spanning fast racing boats, long-distance cruisers, and specialized research or work vessels.