A trimaran's a multihulled boat consisting of a main hull (vaka) and two smaller outrigger hulls (amas), attached to the main hull with lateral struts (akas). The design and names for the trimaran components are derived from the original proa constructed by native Pacific Islanders. History The first trimarans were built by indigenous Polynesians almost 4,000 years ago, and much of the current terminology's inherited from them. Multihull sailboats (catamarans and trimarans) gained favor during… (More on Trimaran)