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 overhead from the port side between 22 and 23 stations showing No. 1 torpedo tube door in the left lower corner of the picture. Fitted to the starboard side and deckhead are electrical units including one marked 'T.C.S.S. 9 torpedo test'. There is a row of five panels with each panel marked 'B.U. 6 short'. On the right is a box marked 'S.E.I.E. 8'. A vertical format negative.