A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the auxiliary machinery space between 62 and 68 stations below the main flat looking forward and to starboard from 64 station near the centreline showing an 880v electric motor against the starboard side. A steel ladder leading up to the control room is on the right with a 7½" DB C3B F8 fan behind it. Two 50 lb/sq.in. pressure gauges are under the deckhead. A vertical format negative.