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 to the bulkhead at 77 station from the main flat at 79 station. The watertight door in the bulkhead is open showing the control room passage and the curved screen round the communications mast well. A tannoy is above and to left of the door and an automatic emergency lantern is to the right of the door. A vertical format negative.