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 auxiliary machinery and gland space (thrust block compartment) between 103 and 107 stations below the main flat. He is looking forward on the port side showing the port propeller shaft torsionmeter and thrust block on the left. A nest of storage drawers is against the forward bulkhead on the right. In the centre is the vertical steel ladder leading up to the aft crew accommodation on the main flat. A vertical format negative.