Underwater hull inspection (UWILD)

An underwater inspection in lieu of drydocking is a class-approved survey of the ship’s underwater hull, conducted afloat by qualified divers or a remotely operated vehicle with real-time video to the attending surveyor, accepted in place of one of the two drydockings normally required in a five-year cycle. It covers the shell plating, rudder, propeller, sea chests, and cathodic protection. Eligibility depends on ship type, age, and the condition of the coating, and a ship with a known structural concern or heavy fouling is sent to dock instead.