Wind powered catamaran with improved gliding - has flat-bottom extensions outboard of hulls, angled up to stay clear of water as long as both hulls are immersed

摘要

The wind-powered catamaran is conventional in concept. However, each of the hulls has a flat-bottomed extension (8, 9) outboard, pref. of full length, inclined to the catamaran waterline (7) and not immersed when it is upright. The inclination is 5 - 30 deg., pref. 10 - 15 deg. and should be such that the extensions do not become immersed as long as the opposite main hull is immersed. The main hull immersed surface (5, 6) also flat-bottomed, may be aligned with their extension surface or angled to it, parallel with the waterline. The extensions may have centre boards (10), perpendicular to them.