Craziness of what KM said there... is with the movie... Hunt for Red October... that was a set, but... the crew did great, in My opinion of making it feel like they were actually in a 'Typhoon' class sub.
The whole set up was on a gimble rig, so that all the diving, turning motions.... were able to be accurately shown... no having the actors leaning to imitate motions... well, they still had to, to compensate for the gimble... but... it looked loads better than them having to act as though the sub was in motion.
Knowing that those subs from WW2 were cramped as all get out... was a credit to the set designers that they got it done nicely... but if not, then the cam crew, did a good job of shooting.... is all I can say. That comment about the cramped conditions, is what I know, having been on the "Drum" there, in Mobile.
Of course, that's a Gato class boat & no idea if a Balao is bigger inside or not.
As memory serves... the ''Stingray'', in Down Periscope, was a Balao class. Thinking on it... having watched Run silent, run deep... the quarters, looked a bit... more snug, than what I recall inside the... Stingray.
M. M.