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 to starboard from the main flat at 81 station showing an emergency equipment locker unit on the left with a cushion seat on top of one of the lockers. Between the locker unit and the starboard side of the boat is the Reavell H.P. air compressor.