A dock constructed in the main of watertight tanks. When these are flooded, the dock is immersed in the sea to a depth where it can receive a ship's hull. As the tanks are pumped out, the dock rises, bringing the ship with it, until the hull is above water. The great value of a floating dock, as against a graving dock which is a permanent structure, is that it can be towed to any place where its services are required.
Subjects: Maritime History.