Correct or incorrect labelling for photo # 2, one thing that strikes me is how crowded the deck of the boat is with the whole crew mustered aft like that.
Considering that the photo shows almost half the length of the boat, and keeping mind that the habitable portion of the pressure hull does NOT extend all the way to the bow or the stern, and also thinking about how much room equipment, controls, bulkheads, periscopes, engines, motors and spare torpedoes take up on the inside, it really gives you an idea of how crowded these 'sewer pipes' really were.
I hadn't appreciated it before until put into perspective with that photo.