A 35mm roll film negative. On board the Rothesay class type 12 frigate Rhyl (1959) in Devonport Dockyard. In the sonar instrument room on 3 deck between 12½ and 16 stations. The photographer is looking to port and aft from the starboard side of the room showing a cabinet for electrical first aid units on the left. A cabinet for a hand controlled change over switch is above two wooden cupboards marked C and D against the inboard bulkhead. The photograph was taken prior to 9 May 1972. A vertical format negative.