A boat lift has one or more pumps that evacuate water from a first flotation tank construct and a second flotation tank construct to create flotation of the boat lift. Modular boat lifts may be constructed according to the invention that have substantial size but are transportable by truck for construction on site.

A boat lift includes four posts and four linear actuators, each attached to one of the posts. Each linear actuator includes an extendable and retractable member oriented for extension and retraction substantially parallel to the post. Ends of a first pair of the extendable and retractable members are connected to a first carrier and ends of a second pair of the extendable and retractable members are connected to a second carrier. A cradle or platform is supported by the first and second carriers. The boat lift may be supported by the ground, by a structure, for example, a dock, a sea wall or a wall of a boat house, or by pontoons.

A boat lift includes four posts and four linear actuators, each attached to one of the posts. Each linear actuator includes an extendable and retractable member oriented for extension and retraction substantially parallel to the post. Ends of a first pair of the extendable and retractable members are connected to a first carrier and ends of a second pair of the extendable and retractable members are connected to a second carrier. A cradle or platform is supported by the first and second carriers. The boat lift may be supported by the ground, by a structure, for example, a dock, a sea wall or a wall of a boat house, or by pontoons.

A bunk for a boat lift includes a bottom portion pivotally configured to attach to one or more lifting beams of the boat lift. A top portion is positionably securable to the bottom portion wherein the top portion comprises includes a boat engaging surface having a first end and a second end wherein the first end is a first distance from a midplane of the top portion and the second end is a second distance from the midplane of the top portion. The top portion is positionable into a first position where the boat engaging surface is in a first position relative to the bottom portion and wherein the top portion is positionable into a second position by moving the top portion end for end relative to the bottom portion wherein boat engaging surface is a second position relative to the bottom portion.

A bunk for a boat lift includes a bottom portion pivotally configured to attach to one or more lifting beams of the boat lift. A top portion is positionably securable to the bottom portion wherein the top portion comprises includes a boat engaging surface having a first end and a second end wherein the first end is a first distance from a midplane of the top portion and the second end is a second distance from the midplane of the top portion. The top portion is positionable into a first position where the boat engaging surface is in a first position relative to the bottom portion and wherein the top portion is positionable into a second position by moving the top portion end for end relative to the bottom portion wherein boat engaging surface is a second position relative to the bottom portion.

An object of this invention is to prevent the collapse of structures such as boat lifts, where the collapse is caused by corrosion of metal fasteners inside conductive material such as moist wood in the presence of external voltage differences, and where the corrosion is prevented by blocking current from flowing through the fasteners.

A boat lift has a transverse flotation tank that joins a first flotation tank construct and a second flotation tank construct. The transverse flotation tank has one or more pumps that evacuate water from the first flotation tank construct, the second flotation tank construct and the transverse flotation tank and create flotation of the boat lift. Modular boat lifts may be constructed according to the invention that have substantial size but are transportable by truck for construction on site.

A boat lift has a transverse flotation tank that joins a first flotation tank construct and a second flotation tank construct. The transverse flotation tank has one or more pumps that evacuate water from the first flotation tank construct, the second flotation tank construct and the transverse flotation tank and create flotation of the boat lift. Modular boat lifts may be constructed according to the invention that have substantial size but are transportable by truck for construction on site.

A wave electricity generator system includes a water craft, a reinforcement beam mounted to a bottom of the watercraft, a power generating unit and a leverage assembly. The leverage assembly includes a connection unit disposed on the watercraft, and a lever 62 connected to the power generating unit and the connection unit. The connection unit includes a rope retaining seat, a rope and a protective pad. The rope retaining seat is disposed above the watercraft and connected to the lever. The rope is disposed around the watercraft, threads through the reinforcement beam, and is connected to the rope retaining seat. The protective pad is disposed between the reinforcement beam and the rope.

A wave electricity generator system includes a water craft, a reinforcement beam mounted to a bottom of the watercraft, a power generating unit and a leverage assembly. The leverage assembly includes a connection unit disposed on the watercraft, and a lever 62 connected to the power generating unit and the connection unit. The connection unit includes a rope retaining seat, a rope and a protective pad. The rope retaining seat is disposed above the watercraft and connected to the lever. The rope is disposed around the watercraft, threads through the reinforcement beam, and is connected to the rope retaining seat. The protective pad is disposed between the reinforcement beam and the rope.