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 67 station to port of the centreline showing the upper part of the radar periscope well. A klaxon horn is under the deckhead with an automatic emergency lantern and a 30 lbf/in² pressure gauge below it. A vertical format negative.