To facilitate the entrance and traveling into a place having a narrow river width and a little water quantity by horizontally laying a belt between a propeller shaft and an engine shaft.

Two propeller propulsion parts are set in the rear of a hull body 1. The propeller propulsion parts are formed of propellers 21, 21' rotated at high speed by one engine 22 set between them and protecting bodies 23, 23' for protecting them from the outer part. Rudder plates 24, 24' capable of changing the direction of the hull body 1 by operating a steering arm 10 are set in the rear of the protecting bodies 23, 23'. Further, since the propeller propulsion parts 20, 20' are arranged above the water level, they never contact the water surface. Belts 27, 27' are arranged in the front and rear of the engine shaft 25. Therefore, the twin-engine propellers 21, 21' are horizontally operated by use of one engine 22 to provide a propulsive force, whereby the hull body 1 can be miniaturized.