A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the generator room between 77 and 92 stations looking forward and up from the main flat at 81 station showing pipe runs and valves under the deckhead. In the lower left of the picture is a tannoy which is above and to the left of the watertight door in the forward bulkhead at 77 station. A vertical format negative.