- Aka (sailing)
The aka of a
multihull sailboat is a member of the framework that connects the hull to the ama(s) (outrigger). The term aka originated with theproa , but is also applied to moderntrimaran s. cite web |url=http://proafile.com/view/weblog/comments/a_primer_on_proas/
title=A primer on proas
accessdate=2007-10-30]The design of the akas depends on the forces it will encounter when sailing. For example, there are two modern variations of the proa, the traditional or Pacific proa, with the ama to the
windward side, and the modern Atlantic proa, with the ama to theleeward . The windward ama provides stability by placing thecenter of gravity far to the windward of thesail , so it is generally heavy. Ropes leading from the mast to the ama provide the force to lift the ama, so the akas must contend mainly with compressive forces, and the weight of the crew, who generally ride on a platform running between the akas.An Atlantic proa or a trimaran rely on an ama to leeward to provide stability. The ama provides stability by moving the center of buoyancy to the leeward side, and well designed leeward amas will also provide dynamic lift to increase the stability further. The aka for a leeward ama must be designed to handle significant amounts of
torque from the lift produced by the ama. Often trimarans will have a platform between the akas, so the crew can ride out on the windward side. While this is not truly necessary from a stability point of view (the ama generally provides a tremendous amount of lift) it does reduce the drag generated by the leeward ama.Origin and use of the term
The term "vaka", like the related terms aka and ama, come from the Malay and Micronesian language group terms for parts of the
outrigger canoe , and "vaka" can be roughly translated ascanoe . A proa consists of a vaka, the main canoe-like hull; an ama, the outrigger; and akas, the poles connecting the ama to the vaka. Thetrimaran uses the same terminology, with a center vaka and amas and akas on each side. [cite web |url=http://www.tridarkaraider.com/
title=The Tridarka Raider
accessdate=2007-10-30]References
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