Abstract: Outriggers of a trimaran mounted on hinged arms for swinging from a sailing position to an alongside position are braced in sailing position in each case by a tension cable having its ends fixed with respect to the outrigger at the connection with the arms and its center detachably fastened to an eye affixed to the main hull. Each tension cable is tightened by a bridle bridging the midpoint of the cable pulled towards the outrigger by a tackle of which the free end is secured to the main hull. If the point at which the middle of the tension cable is secured to the main hull is lower than the places where the ends of the cable are anchored, tightening the tension cable tends to relieve the arms of strains produced by the buoyancy of the lee outrigger.