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.