Abstract: A pontoon boat lift features tanks adjacent opposite sides thereof with upper walls slopes upwardly in a laterally outward direction. In lowered positions of the tanks, top ends of the sloped walls remain above water for visual and physical guidance of the pontoon boat into a position placing pontoons thereof between the outwardly sloped walls and over submerged portions of the lowered tanks, thereby allowing subsequent seating of the pontoons on said sloped walls during raising of the air tanks to lift the pontoons from the water. Buoyancy control for raising and lowering of the tank is effected by controlling air and water content thereof. The tanks are arranged to trap sufficient air therein to keep the lift buoyant to prevent sinking without using legs to support the boat lift on the sea, lake or river bed. The lift is adjustable in width and length for boats of varying size.

Abstract: A pontoon boat is manufactured using sectional pontoons of rotationally molded thermoplastic material. The pontoon sections are engaged end to end using integral lugs and sockets on the ends of the pontoon sections. Each section has a head located above the main hull portion of the pontoon. Channels engage opposite sides of the heads and extend along the pontoons to ensure the coupling of the pontoon sections. These channels also couple the pontoons to a deck carried on transverse beams joining the channels.