HALF-DISPLACEMENT TYPE HIGH-SPEED CRAFT

PURPOSE:To perform the reduction of pitching without fail, by installing a strut projectingly downward from a stem part bottom of a half-displacement type high-speed craft, while attaching a fin to this strut, and preventing the fin at navigation during billowing from being exposed upward from the surface of the water. CONSTITUTION:A strut 14 is installed projectingly downward from a stem part bottom of a half-displacement type high-speed craft, and a fin 12 is attached to the strut 14. This fin 12 makes its elevation angle movable at will by a hull motion sensor 15 bia a control unit 16, aiming at reduction in the pitching of the hull at navigation. And, the fin 12 is attached via the strut 14 whereby at the time of sailing in waves, the fin is in no case exposed upward from the surface of the water, thus reduction in the pitching is surely performed.