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 crew accommodation space between 103 and 117 stations on the main flat looking up and slightly aft from the centreline at 105 station showing the submarine escape tower with the hatch closed. A sign reading 'Red cross locker above' is under the deckhead aft of the tower.