Trimaran sailplan. They contribute to drag when heavily immersed, and their level of immersion indicates when to reef. Two types of trimaran exist: the regular trimaran and the open trimaran, which features a trampoline between the hulls instead of plating. Trimarans have a number of advantages over comparable monohulls (conventional, single-hulled sailboats). Given two boats of the same length, the trimaran has a shallower draft, a wider beam, less wetted area, and is able to fly more sail area. In addition, because of the righting moment provided by the wide beam, trimarans do not need the weighted keel that is required
Trimaran by Austal. The DARPA is experimenting with the trimaran design, and in 2012 awarded SAIC a contract to perform Phases 2 through 4 of the ACTUV Program. The contract is expected to be completed by August 2015. According to American usage, there are three terms that describe the main components of catamarans and trimarans, namely: “vaka”, “aka” and “ama”. These terms come from the Malay and Polynesian language group terms for parts of the outrigger canoe (The above terminologies reflects only American usage. In the UK the main hull of a trimaran is called simply the "main hull" or "centre