Abstract: A catamaran type vessel that includes two rigid side hulls connected by a connector to form a rigid form containing a usable space. The vessel contains a lowered and lifted platform together with the platform drive unit. The platform is a separate portion of the aft part of the deck, in the form of a flat frame with a usable overlay fixed on the surface of the frame. An edge of the platform in the upper position cooperates with an edge of the aft part of the deck, with the platform frame being attached to the horizontal edges of two supports. The rear vertical edge of each support is connected by axes of rotation with a pair of rigid arms in the pantograph system connected with two horizontal axes of rotation attached on the other side of the rigid arms to the vessel hull connector wall.