A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the forward torpedo compartment looking to starboard, aft and up from the centreline between 31 and 32 stations. Mounted on a support beam is a notice titled 'Oxygen candles Mk. IV - Instructions for pyrotechnic ignition'. Another notice is partially obscured by a framework and its title is 'Instructions for synchronising forward remote control'. Two pressure gauges are on the starboard side. Against the aft bulkhead are an amplifier assembly control panel and a seawater battery drive panel.