PURPOSE: To carry and elevate a boat (includes other floater) between a boat housing equipment on the land or the water and the water surface part.

CONSTITUTION: Two fixed rails 4 for carrying the boat carrying elevating means 6a, 6b are laid along the construction 1 for carrying a boat arranged across a boat housing equipment 3 and a boat landing place 2 on the water surface part. On the other hand, switching rails 5 are arranged in the boat housing equipment 3 and the boat landing place 2 respectively so as to move reciprocatingly the plural sets of boat carrying elevating means 6a, 6b in the direction mutually passed. Thereby, at least a set of boat carrying elevating means enables the boat to be carried actually in the process of its reciprocating movement and the traffic jam for waiting the boat housing in or cut can be prevented even at the time zone in which the boat housing in or out is concentrated.