A boat lifting assembly includes a cradle for carrying a boat mounted
between three pilings on each cradle side. A pair of support housings is
affixed to the pilings on each cradle side. A pair of hydraulic lifts are
housed in the housings and connected to the cradle for moving same
vertically. Each lift includes a horizontally extensible piston carrying
a piston pulley block and a stationary hydraulic cylinder. Three cables
have one end portion threaded between the pulleys of the block and the
cradle. Transition pulleys are supported by the housing and direct the
cable vertically for moving the cradle when the block is moved.
Additional pulleys and various anchor points may be employed to provide
for vertical lifts of 1.5, 2.0 and 3.0 times the distance of movement of
the piston. The housings are in the same plane as the cradle deck and/or
dock.