PURPOSE: To surely prevent a spray with no difficulty for carrying a ship body by additionally providing a bag-shaped unit, which is swollen in a wing shape in the horizontal direction by an internal pressure of a bag-shaped skirt, in its both right and left side parts or the like and swelling the bag-shaped unit only when required.

CONSTITUTION: A bag-shaped skirt 2, in which air is stored, is arranged in an outer side peripheral part of a ship body 1. Here an opening part 6 is formed in an outer side central part of the bag-shaped skirt 2, further for maintaining a shape of the opening part 6, a net 7 is additionally provided. A spray- preventing device 5, formed in a wing shape, is arranged in an end part of the opening part 6, further a shape-maintaining cloth 8 is additionally provided in the inside of the spray-preventing device 5 for maintaining the shape at the time of inflation. When an inner part of the bag-shaped skirt 2 is charged with air, it partly passes through the opening part 6, and also an internal part of the spray-preventing device is charged with the air. Thus by swelling the spray-preventing device 5 in the wing shape, the spray is prevented from falling on passengers.