Underwater inspection in lieu of dry docking

Underwater inspection in lieu of dry-docking, UWILD, is a class-approved underwater hull examination that substitutes for one of the two bottom surveys required in the five-year cycle, so the ship avoids one dry-docking. Divers or an ROV give the attending surveyor a live, recorded video feed of the shell plating, sea chests, rudder, propeller, anodes, and the coating, with most societies requiring two to three meters of underwater visibility. Class normally limits UWILD to vessels under 15 years with a sound coating and an in-water-survey notation, and the second docking in the cycle must still be a true dry-docking. A UWILD takes 24 to 48 hours against weeks in a yard.