Abstract: A water vehicle moving on or in a liquid and including a flotation element (1) that is connected by a connection member (6) to a carrier (3), the water vehicle being characterized in that the connection member (6) is shaped so as to enable the carrier (3) to assume at least two positions, namely:—a raised position where the longitudinal axis of the carrier (3) and those of the flotation element (1) substantially extend into the same horizontal plane, the carrier (3) then being on the surface and capable of making up a central shell; and—a lowered position where the carrier (3) extends under the plane including the longitudinal axis of each of the flotation element (1), the carrier (3) then being submerged.