A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the generator room below the main flat between 77 and 82 stations, this space being irreverently known as the snake pit. He is looking aft, to starboard and down from the centreline at 78 station showing a hinged drop-down front locker on the right. The ladder leading up to the main flat is on the left with the distilling plant control and instrument panel behind it. An automatic emergency lantern is mounted on a pillar in the top left of the picture. A vertical format negative.