A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the control room passage between 56 and 70 stations on the main flat looking up and to starboard and slightly forward from 67 station showing a distribution box made by Bluntray (Engs) Ltd above an automatic emergency lantern and a salinometer on the right. The Ademar mast is in the centre.