A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the control room between 59 and 69 stations on the main flat looking to port and aft from the port side at 64 station showing the snort masts control valves, pipework and gauges on the left with the 'O' tank trim pump handwheel box on the extreme left of the picture. A barometer is in the lower centre with a loudspeaker to the right of it. The vertical high pressure direct blow main panel with taps numbered 1, 2, 4, 6 and 7 is on the right with gauges for Q, D1 and D2 tanks next to it. A vertical format negative.