Abstract: A system for transferring a vessel between a first body of water having a first water level and a second body of water having a second water level includes a barrier separating the first body of water from the second body of water. The system also includes a transfer structure adjacent the barrier for receiving the vessel to be transferred between the first and second bodies of water, and a transfer apparatus adjacent the barrier for moving the transfer structure between a first position and a second position. The upper portion of the barrier includes a barrier door that is movable between an opened position when the transfer structure is in the second position to allow the vessel to move into and out of the transfer structure, and a closed position when the transfer structure is in the first position.