were the builders of the first commercial F-31 trimaran. Designs by Ian Farrier that later became the Corsair F-31, and eventually Corsair 31 (aft cockpit and aft cabin versions), were first built by Ostac Pty Ltd in Australia. Introduced in 1991, the Ostac F-31 immediately became very successful on the race course and quickly attracted worldwide recognition. A trimaran is a multihull boat that comprises a main hull and two smaller outrigger hulls (or "floats") which are attached to the main hull with lateral beams. Trimarans are most commonly sail-driven yachts designed for recreation or racing, but there are a few trimaran ferries and warships. According to American usage, there are three terms that describe the main components of catamarans and trimarans. They are: “vaka”, “aka” and “ama”. These terms come from the Malay and Polynesian language group terms for parts of the outrigger canoe. Vaka is the canoe or main hull. Aka is the framework member that connects the vaka (hull) to the ama (outrigger, or “float”). Ama is the outrigger, connected to the vaka by an aka.