A roll film negative. A close view of the hull outfit 18 aperture in the hull of the commando carrier Hermes (1953) in number 10 dry dock in the north yard of Devonport Dockyard in May 1973 towards the end of her conversion from a fixed wing aircraft carrier to a commando carrier. She recommissioned after conversion on 18 August 1973. The photographer is looking to starboard from the floor of the dock near the keel showing a six to seven inch hole in the hull marked HO 18 (Hull Outfit 18), which is possibly for the sonar type 765 transmitter between 17 and 18 stations or the sonar type 765 receiver between 19 and 20 stations.