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 between 59 and 69 stations looking to starboard and up from 64 station showing the deckhead above the main action console. A control transponder and a large number of junction boxes and fuse boxes are under the deckhead, as is a gauge showing excess sea pressure on one side and excess air pressure on the other.