A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the electrical maintenance room between 101 and 103 stations on the starboard side of the main flat looking up into the aft starboard corner showing six test power sockets above a main motor box. An electrical unit is laying on a shelf in the foreground. Storage shelves are against the boat's side. A vertical format negative.