PURPOSE: To safely enjoy the skiing by constituting the skiing ground of plural pieces of sections in which water is stored, formed in the longitudinal direction of a vessel in the lower part in a hold, a float placed on the water surface in the section, a floor plate having the inclined surface fixed onto the float, and a snow making machine for accumulating artificial snow on the floor plate.

CONSTITUTION: The water surface level in plural pieces of sections 1 formed in the longitudinal. direction of a vessel in the lower part in a hold of a large- sized vessel is lower stepwise, for instance, extending from the sten A to the bow B. A floor plate 4 is fixed onto a float 2 through an arm 5. therefore, it is always maintained horizontally even if the vessel rolls or pitches. Also, each floor plate is connected to each other so as to be bendable, and even if an inclination angle of the floor plate 4, that is, an inclination angle of a slope is varied due to a variation of the water surface level in the section 1, it is possible to follow it. In such a state, a slope is made on the floor plate 4 by allowing artificial snow to fall in a hold by a snow making machine, and a skier can slide on the slope. In such a way, skiing can be enjoyed safely in the course of navigation.