Abstract: A roller assembly facilitates travel of a watercraft hull on a floating dock having a longitudinal, keel-receiving valley with a pair of flanking ridges supporting opposite sides of the hull during docking and launching of the craft. Pockets in the ridges contain wheels mounted on circumferential planes parallel to the ridges for rotation on axles seated in the pockets. The upper portions of the wheels protrude above the crests of the ridges and the axle end bearing portions cooperate with the seats in the pockets to list the circumferential planes toward the valley and approximately perpendicular to the hull sides. For optimal performance, two or more roller assemblies can be arranged in-line and spaced apart longitudinally in each of the ridges. A brake stops the docking motion of the watercraft onto the dock. Multiple docks can be serially connected without use of special tools or underwater assembly steps.

Abstract: In a lift for mooring a boat stern-on, a pair of horizontally spaced guide members is fixed to the sea wall. A frame is fixed to a pair of substantially parallel hydro-pneumatic buoyancy tanks to provide a flotation platform for supporting the hull of the boat. The stern end of each of the tanks is connected to the guide members. The guide members limit movement of the platform away from the sea wall and along the sea wall but permit vertical reciprocation of the stern ends of the lift tanks in unison and restrict the lift from listing during operation.

Abstract: A plastic rotationally molded polyethylene buoyancy tank for boat lifts allows connection of steel to lengthwise grooves molded into each side of the buoyancy tank. Preferably, a plastic bulkhead is formed within the tank during its molding process. A segment of framing steel is bracketed between a pair of inwardly tapered compressible opposed grips. The compressible grips each have outwardly tapered slots with mating tapered rigid inserts. With the inserts partially seated on the grips, the grips are slipped lengthwise or pressed laterally into their respective grooves. Bolts extending through the grips into threaded holes in the inserts are tightened to pull the grips over their tapered inserts. This spreads and compresses the grips in their respective grooves, locking the brackets and connecting steel in place on top of the tanks.

Abstract: A plastic rotationally molded polyethylene buoyancy tank for boat lifts allows connection of steel to lengthwise grooves molded into each side of the buoyancy tank. Preferably, a plastic bulkhead is formed within the tank during its molding process. A segment of framing steel is bracketed between a pair of inwardly tapered compressible opposed grips. The compressible grips each have outwardly tapered slots with mating tapered rigid inserts. With the inserts partially seated on the grips, the grips are slipped lengthwise or pressed laterally into their respective grooves. Bolts extending through the grips into threaded holes in the inserts are tightened to pull the grips over their tapered inserts. This spreads and compresses the grips in their respective grooves, locking the brackets and connecting steel in place on top of the tanks.

Abstract: In a lift for mooring a boat stern-on, a pair of horizontally spaced guide members is fixed to the sea wall. A frame is fixed to a pair of substantially parallel hydro-pneumatic buoyancy tanks to provide a flotation platform for supporting the hull of the boat. The stern end of each of the tanks is connected to the guide members. The guide members limit movement of the platform away from the sea wall and along the sea wall but permit vertical reciprocation of the stern ends of the lift tanks in unison and restrict the lift from listing during operation.

Abstract: In a lift for mooring a boat stern-on, a pair of horizontally spaced guide members is fixed to the sea wall. A frame is fixed to a pair of substantially parallel hydro-pneumatic buoyancy tanks to provide a flotation platform for supporting the hull of the boat. The stern end of each of the tanks is connected to the guide members. The guide members limit movement of the platform away from the sea wall and along the sea wall but permit vertical reciprocation of the stern ends of the lift tanks in unison and restrict the lift from listing during operation.

Abstract: A plastic rotationally molded polyethylene buoyancy tank for boat lifts allows connection of steel to lengthwise grooves molded into each side of the buoyancy tank. Preferably, a plastic bulkhead is formed within the tank during its molding process. A segment of framing steel is bracketed between a pair of inwardly tapered compressible opposed grips. The compressible grips each have outwardly tapered slots with mating tapered rigid inserts. With the inserts partially seated on the grips, the grips are slipped lengthwise or pressed laterally into their respective grooves. Bolts extending through the grips into threaded holes in the inserts are tightened to pull the grips over their tapered inserts. This spreads and compresses the grips in their respective grooves, locking the brackets and connecting steel in place on top of the tanks.

Abstract: In a lift for mooring a boat stern-on, a pair of horizontally spaced guide members is fixed to the sea wall. A frame is fixed to a pair of substantially parallel hydro-pneumatic buoyancy tanks to provide a flotation platform for supporting the hull of the boat. The stern end of each of the tanks is connected to the guide members. The guide members limit movement of the platform away from the sea wall and along the sea wall but permit vertical reciprocation of the stern ends of the lift tanks in unison and restrict the lift from listing during operation.

Abstract: A buoyant walkway module for a boatlift is formed from a plurality of pneumatically discrete elongated compartments. Each of the compartments has a substantially flat upper horizontal exterior surface and complementary exterior end surfaces. With the end of one such module in abutment with the complementary end of another such module, the upper horizontal surfaces lie in the same plane so as to provide a suitable walkway for the boatman. Preferably, the end surfaces are perpendicular to the horizontal surface so as to provide maximum stability in the walkway.With the modules positioned in end-to-end relationship, they are coupled together by a flat plate disposed across the upper exterior surface of their junction and by a pair of straps extending longitudinally across the lower exterior surface at their junction.

Abstract: A buoyant walkway module for a boatlift is formed from a plurality of pneumatically discrete elongated compartments. Each of the compartments has a substantially flat upper horizontal exterior surface and complementary exterior end surfaces. With the end of one such module in abutment with the complementary end of another such module, the upper horizontal surfaces lie in the same plane so as to provide a suitable walkway for the boatman. Preferably, the end surfaces are perpendicular to the horizontal surface so as to provide maximum stability in the walkway.With the modules positioned in end-to-end relationship, they are coupled together by a flat plate disposed across the upper exterior surface of their junction and by a pair of straps extending longitudinally across the lower exterior surface at their junction.

Abstract: A lift for docking a personal watercraft from a body of water has a shell with a cradle for supporting the watercraft and an open end for horizontally receiving the watercraft. A buoyant filler within the shell floats it with its open end approximately aligned with the water surface. A replaceable skid plate substantially centered on the open end of the shell engages the tapered bow portion of the watercraft during the docking process and guides the watercraft into substantially a centered position on the shell and raises the watercraft upwardly and drives the shell downwardly as the watercraft is horizontally transferred onto the shell from the body of water. The shell has two pairs of posts, one pair extending forwardly from the front and one pair rearwardly from the back, one proximate each of the sides of the shell. Each post has a flange about its free end.

Abstract: In a front mounted lift for watercraft, the torque exerted by the lift on the dock is limited by a combination of a first buoyant force, being air trapped within the lift tanks, and a second buoyant force, being flotation devices connected to the rear of the lift. In a preferred embodiment, the primary buoyant force is achieved by the extension of an air supply and exhaust hose into each tank compartment to a level below the uppermost level of the tank chamber. When the water level in each tank compartment covers the hose opening, the air trapped in the tank provides a buoyant force to counter most of the submerged lift weight. The depth of the hose is selected so that the weight of the lift slightly exceeds the primary/buoyant force. This permits the lift to sink but significantly minimizes the torque exerted on the connection of the lift to the dock. The secondary buoyant force preferably consists of a pair of buoyant guides which prevent the rear of the lift from sinking to an undesirable depth.

Abstract: A lift for water vehicles comprising a pair of vertical pipes or tracks attached adjacent their upper ends to one side only of a dock structure which is positioned alongside a body of water, a tank assembly having a roller assembly thereon for engaging the sides of the pipes for rolling upwardly and downwardly thereon, the tank assembly having a tank mounted thereon and an upper opening for introducing air into the tank to displace water therefrom through a lower opening at the bottom of the tank so as to cause the tank to rise, the tank assembly having a pair of spaced padded blocks for supporting a water vehicle thereon, the roller assembly having roller thereon adapted to rise along the inboard sides of the pipes when the tank assembly moves vertically in response the introduction of air to and removal of air from the tank, whereby, when a water vehicle is supported on the padded blocks and the tank assembly is in its lowermost position, air can be introduced into the tank while water is forced outwardly f