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 and aft 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'. At the bottom of this support beam is a label 'Mk. 23 power load attachment'. On the starboard side are a T.C.S.S. 9 3 phase monitoring alarm bell and a 'Reduced H.P. air to pneumatic tools panel'. Against the aft bulkhead are an amplifier assembly control panel and a seawater battery drive panel. A vertical format negative.