PURPOSE: To allow the direction change, lateral movement and rotation of a vessel by defining water passages extending through rotatable members with duct members, and adjusting propulsion apparatuses with rotation adjustment sections so that the vessel can be driven at an angle.

CONSTITUTION: Conical members 14 are rotatably supported at both ends of four slender hollow cylindrical casings 12 and are kept in slide contact with the semiconical recess 19 of a housing 15 in this vessel 10. Each conical member 14 has a cylinder duct forming a water passage 20, and a propulsion unit 18 is provided there. During a normal navigation, water is guided to the water passage 20 from a front propulsion unit 18 through a vertical duct 21 and the opening 16 of the housing 15, and it is further accelerated by a rear propulsion unit 18 and is spouted via a duct 23 and a rudder 25. When the vessel 10 is to be changed in direction, laterally moved or rotated, the front and rear conical members 14 are rotated to the right or left by 90°, the stream is sucked from the side hole 16a of the housing 15, and it is spouted from the duct 23 rotated by 90°. The vessel 10 can be changed in direction, laterally moved or rotated without being moved.