Abstract: A floating dock boat lift comprises a flat deck and a parent structure to which the deck is hinged. The free end of the deck over-lies a variable buoyancy chamber communicating by pipes or hoses to an inlet air pump on or near the parent structure and to an air release valve on or near the deck. Alternately, air venting, for buoyancy control in under-deck compartments, may be facilitated through valves at each compartment. The deck is provided with a combination metal and wood boat-supporting keel brace and underlying reinforcement members.