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 starboard, slightly aft and down from the main flat at 79 station showing the hatch leading down below the main flat to the space containing the distiller control and instrument panel, oily bilge pump, main ballast pump and lubricating oil coolers, filters and pumps. This space is irreverently known as the snake pit. An emergency equipment locker unit is on the right with a fire extinguisher and a stowage rack for a fire hose fitted to it. A vertical format negative.