A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the aft torpedo compartment between 108 and 117 stations on the main flat looking to port, aft and down from 109 station showing the valves below the submerged signal ejector. the four valves are marked 'drains', 'vent', 'equalising' and 'firing'. Two fire extinguishers are on the right and a large tin of Swarfega is on the deck under a sink. A vertical format negative.