Abstract: A lift for water vehicles comprising a pair of vertical pipes or tracks attached adjacent their upper ends to one side only of a dock sructure which is positioned alongside a body of water, a tank assembly having a roller assembly thereon for engaging the sides of the pipes for rolling upwardly and downwardly thereon, the tank assembly having a tank mounted thereon and an upper opening for introducing air into the tank to displace water therefrom through a lower opening at the bottom of the tank so as to cause the tank to rise, the tank assembly having a pair of spaced padded blocks for supporting a water vehicle thereon, the roller assembly having rollers thereon adapted to rise along the inboard sides of the pipes when the tank assembly moves vertically in response the introduction of air to and removal of air from the tank, whereby, when a water vehicle is supported on the padded blocks and the tank assembly is in its lowermost position, air can be introduced into the tank while water is forced outwardly f