A large capacity boat lift includes a lift assembly mounted on each side of a boat supporting platform. Each lift assembly includes a support structure that carries a winder. A lifting cable is operably attached at each of its ends to respective sections of the winder. A drive mechanism operates the winder in first and second directions to selectively wind the cable onto and off of the winder. The cable movably interengages a pair of pulleys carried by the platform. A section of the cable between the pulleys is engaged with the support structure such that winding the cable onto the winder raises the platform and unwinding the cable from the winder lowers the platform.