A sheet film negative, possibly acetate. The submarine Sealion (1959) undergoing a refit in Admiralty floating dock AFD60 (1966) at Faslane. A close view of the port side of the stern taken from the floor of the dock looking to starboard. The port hydroplane, rudder, torpedo tube and overtaking light are in the picture. Scaffolding is around the port propeller. An Admiralty copy negative of a whole plate photographic print. A vertical format negative.