A boatlift buoyancy system for assisting in maneuvering a boatlift while in the water by adding buoyancy to the boatlift. The boatlift buoyancy system includes a first tube and a second tube attachable to the horizontal support beams of a boatlift that are capable of receiving of volume of air and/or water. A first hose and a second hose are fluidly connected to the first tube and second tube respectively for delivering pressurized air when buoyancy is desired for the boatlift. The first tube and the second tube also have a first aperture and a second aperture respectively within lower portions thereof for allowing for the draining of water when pressurized air is input into the tubes.

A heavy duty low-profile watercraft lift (10) for lifting small watercraft into and out of the water adjacent to a dock (12). The lift (10) comprises a single heavy-duty column (22) having a winch (28) mounted on the top thereof for raising and lowering a carriage (26) that is engaged with a track (32) formed on the column (22). Adjustable arms (72) and rails (74) on the carriage (26) enable adjustment to fit a watercraft. Opening (108) allows a pin to be inserted therethrough to hold the carriage (26) in a raised position. The winch (28) can be mounted to any side of the column (22) to meet the needs of a particular installation. The lift (10) of the present invention provides a compact, efficient, and visually appealing dockside lift.

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. This secondary force further reduces the torque on the dock. These buoyant guides also serve to direct the watercraft into its proper position on the lift during the landing process and to support the watercraft in its operational attitude on the lift when the watercraft is raised out of the water.

A drive-on dry dock (10) especially suited for a boat (12) longer than about thirty feet and weighing more than about seven thousand pounds. The dock (10) includes a platform (14), a guide (16), and a lift (18). The platform (14) includes an aft section (20), a forward section (22), and a hinge section (24) therebetween. The guide (16) defines a path for movement of the boat (12) from the aft section (20) to a rest position whereat the boat's bow engages and is supported by the forward section (22). The lift shifts the platform (14) between a first condition in which the aft section is only buoyant enough to support itself and so can be downwardly flexed form a ramp for the boat (12) and a second condition in which the aft section is sufficiently buoyant to lift the boat out of the water.

A modular pump barge and walkway system having a modular subsystem of pump barges and a modular subsystem of walkways releasably attached thereto. Each of the pump barges has a top deck and four side walls, wherein each of two oppositely disposed side walls has a recess disposed therein with a bottom shelf and a pair of holes. Each of the barges has a link pin assembly for interconnecting with an adjacent barge, comprising a support plate and a pair of vertically disposed pins, the support plate arranged so as to be removably attachable to the top deck so as to cover the recess, the pins being disposed so as to be mated with and removably inserted into the pair of holes disposed within the bottom shelf of the recess when the support plate is attached to the top deck. A link plate has a pair of parallel slots juxtaposed so as to allow placement therethrough of the pins of the link pin assembly, the link plate being removably and slidably inserted between the support plate and the bottom shelf of the recess when the link pin assembly is attached to the barge. Thus, the link plate provides interconnection of adjacent barges with independent vertical translational movement therebetween. The modular subsystem of walkways also has a plurality of floating walkways interconnected to each other in serial fashion at each of two oppositely disposed ends thereof in pivotable hinged relationship therebetween.