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 between 59 and 69 stations looking slightly aft and almost directly up into the conning tower from the main flat at 61 station. The lower hatch is open. The dimmer conning tower lights fuse box, signalling lantern resistance box, conning tower lights fuse box and the klaxon horn are mounted on the transverse frame abaft the hatch.