Abstract: A proa sailing vessel has spaced hulls each having underwater shapes which are substantially symmetrical about a central athwartship axis and a mast which may be pivoted between forwardly inclined attitudes relative to the respective ends of the vessel. The sail is in the form of an isosceles triangle which is set to leeward of the mast whereby either opposed edge may be selectively tensioned between the forwardly inclined mast and the front end of the vessel. The mast extends upwardly from the leeward side of the main hull and is inclined to leeward to assist in self-righting or the vessel.