When I was about 16 yrs. old we went to Norfolk naval base and actually toured a sub like that.
Can't remember which one it was, but it was a decommissioned sub from WW11.
It was very cool to see, but I have no idea how a person could spend as much time as they did out to sea on those things.
Very small and cramped. Not to mention being stuck in there with a bunch of dudes that burp, fart and perspire like the rest of us do.
I'm glad there are people that can do it, but I ain't one of them.
Well we were the, we also toured the USS Lexington,(pretty sure that's the one it was anyway). Which is a aircraft carrier.
It was not used in wartime anymore, but still used for training purposes.
That thing was huge! At least it was when we were standing on the deck. Bet it looked a lot smaller if you were in a jet getting ready to land though.
They took us down below where the jets are kept below the deck and all through the ship.
Spent about 3 hours on board. Very cool!