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 to port, aft and down from the main flat at 91 station showing the port and starboard pump starter units against the aft bulkhead at 92 station. A hand pump is in the centre and the opening into the motor room is on the left. A vertical format negative.