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 from 64 station showing the main action console and chart table. A Decca Navigator wireless circuits receiver is just above the table on the right with a speed indicator in the centre and a bearing indicator on the left. Under the deckhead in the centre is a gauge showing excess air pressure on the right and excess sea pressure on the left.