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 the proa, but is also applied to modern trimarans. A multihull is a sailing ship with more than one hull. ... Traditional wooden cutter beating. ... A hull is the body or frame of a ship or boat. ... AMA is used as an abbreviation for the following: Academy of Model Aeronautics Alberta Motor Association American Management Association American Marketing Association American Medical Association American Motorcyclist Association American Music Awards Associación Médica Argentina Australian Medical Association Against medical advice - a patient that leaves a medical facility early and against... The Proa is a two hulled vessel with unequal parallel hulls, superficially similar to an outrigger canoe. ... A trimaran is a multihull boat consisting of a main hull and two smaller outrigger hulls (amas), attached to the main hull with lateral struts (akas). ...

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 the leeward. The windward ama provides stability by placing the center of gravity far to the windward of the sail, 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. Windward is the side of a boat into which the wind is blowing. ... Leeward is the side of a boat away from the direction where the wind is coming (i. ... In physics, the center of gravity (CoG) of an object is the average location of its weight. ... A sail is a surface intended to generate thrust by being placed in a wind; basically it is a vertically oriented wing. ... A mast is a pole which holds a sail of a boat, see mast (sailing). ...

An Atlantic proa or a trimaran rely on an ama to leeward to provide stability. The ama provides stability by moving the center of bouyancy 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. There are multiple definitions of lift: Lift, an aerodynamic force. ... The concept of torque in physics, also called moment or couple, originated with the work of Archimedes on levers. ... For a solid object moving through a fluid or gas, drag is the sum of all the aerodynamic or hydrodynamic forces in the direction of the external fluid flow. ...