a submersible, floating structure used as a dry dock, having a floor that is submerged, slipped under a floating vessel, and then raised so as to raise the vessel entirely out of the water.
A structure that can be submerged to permit the entry and docking of a ship and then raised to lift the ship from the water for repairs. Also called floating drydock.
A dock that is supported by metal pipes on which it can move up and down with the rise and fall of the water level.
