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 and to port showing the vertical ladder leading up to the aft accommodation on the main flat in the left foreground with the port propeller shaft brake beyond it. The shaft thrust block and a filing cabinet are against the forward bulkhead. A large air bottle is against the port side of the boat. A vertical format negative.