An auxiliary floating drydock is a type of US Navy auxiliary floating dry dock. Floating dry docks are able to submerge underwater and to be placed under a ship in need of repair below the water line. Water is then pumped out of the floating dry dock, raising the ship out of the water. The ship becomes blocked on the deck of the floating dry dock for repair. Most floating dry docks have no engine and are towed by tugboats to their destinations. Floating dry docks come in different sizes to accommodate varying ship sizes, while large floating dry docks come in sections and can be combined to increase their size and lift power. Ballast pontoon tanks are flooded with water to submerge or pumped dry to raise the ship.

A dry dock is a narrow basin or vessel that can be flooded to allow a load to be floated in, then drained to allow that load to come to rest on a dry platform. Dry docks are used for the construction, maintenance, and repair of ships, boats, and other watercraft.