When I toured USS Bowfin 2 things struck me, how big it seamed but there were probably only 6 tourists on board and would have had a crew of 70 ish + Torpedoes making it quite claustrophobic but also as it was floating that even a small swell caused a substantial roll. Not the nicest feeling. But back to the Sky Series I also gave up on series 1 after 3 ep as I kept harking back to the film and have not yet looked at ser 2
As to the Uboat in Chicago. It was closed for maintainance when I was there. But even from the outside it was substantialy smaller than Bowfin. and you could see how the Das Boot Chief would have easily had a breakdown
Respect to any Submariners