A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the control room passage between 69 and 77 stations on the main flat looking to starboard and up from the entrance to the crew's washplace at 76 station showing distribution boxes C3C, C4C and A421. Three valve handwheels are under the deckhead. A vertical format negative.