Interesting points. Not far from where I live is the U.S.S. Torsk, a 'Tench' class sub, a relative of the Gato/Balao. In case you're interested, they have a virtual tour here:
http://www.usstorsk.org/virtualtour/index.htm
Click 'enter tour'. The left side of each page lets you select a compartment, and the right links give different views. I've been aboard several times, and this was the first time I've seen the plot room below the control room, or the conning tower, since they were always closed.
Funny story. The first time I toured the sub, I was in the control room. Across the chart table from me was an unacompanied boy about 7 years old. Right in front of him, I mean
inches from his nose, was a sign that read "Caution: Open Hatch!", with an arrow pointing down to the plot room hatch. He took one step to his right and...
fwip! He fell right through the hatch. I heard him yell, and moved to help. Fortunately for him, one of the maintenace crew was climbing the ladder up, and caught him. He was more scared than anything. From then on, that hatch was closed.
Sigh!
When you get a good sized tour group come through, it's claustrophobic. The captain's cabin seems about right for Traveller stateroom to me. Even the XO had to share his cabin with two other officers!
Thanks for the fleet sub link!