Abstract: The present invention relates to a boat lift including a base structure a cradle connected with the base structure and configured to support a boat, and a plurality of pontoons connected with the base structure for floating the boat lift on a water surface. The pontoons include a plurality of modular floats such that boats of varying weights are lifted and boats of varying centers of gravity are lifted levelly. The present invention also relates to a method of employing the boat lift.

Abstract: The invention is of a modular boat lift supported by floating it on the water surface using pontoons. The lift mechanism is a parallelogram linkage supporting a cradle. Movement of the parallelogram linkage is powered by aqueous hydraulic cylinders using a water pump that preferably is operating using household water, but can also operate using ambient water passed through a sea strainer. Mechanical locking mechanisms freeze the hydraulic cylinder pistons in position and hold the lift in its most upraised position without regard to water pressure in the cylinders. All relevant aspects of the structure are modular or adjustable so that the capacity of the lift to accommodate heavier or lighter boats can be readily altered, and this is done in the field. The distance between pontoons can be adjusted, the distance between the sides of the cradle, called boat bunks, can be varied, the height of the boat bunk relative to the remainder of the structure can be varied.