Hi Nathan, welcome to rc naval combat in general, and to the wierdo club in specific Where are you located?
Welcome aboard Nathan. I can't welcome you to the sub weirdo club, but would be happy to welcome you to the Predreadnought/Armored Cruiser weirdo club should you care to join that one[8D]
Q: Why do submariners call their vessels boats instead of ships? A: Ships are targets. Welcome to the world of model warship combat.
I am interested to see how you get the sub to work. I have a 1/144scale model of U-boat line layer sub and she is pretty damned small. So small I do not think I could arm her at all.
It will be a challenge, but the first thing is to pick a sub that had high displacement. I-400 and the 20's steam powered subs are much bigger that many of the diesel boats built for WW2. Not that you are getting much more space than a large destroyer Mike3
Perfect material for an "itty bitty boat/ship" effort. Space constraints are indeed quite similar for both the boats and the ships that were tasked with hunting them down/protecting convoys against them so if you keep half an eye out on any of the destroyer-related activities around, you may find some ideas or inspiration that could help you with your sub.
Speaking of small things. There is a company in Illinois that I have been conversing with about tiny motor controllers. Pick up one for my Mogador that is the size of a penny! They are leaning towards producing a water proof version of it. If we give them a push, it may just happen!
Have you considered the french Surcouf submarine? Not so small as some others, a deeper rather than wider hull (might help with stability)and gun armed to boot.
You'll definitely have to go for a big gun type club. The small gun clubs do not allow torpedoes. I think there are some subs in Katori's club, but I am not certain if they can submerge or not, and to fire their torpedoes they have to tap a firing button on the bow of their sub against the enemy ship. You should really look at the 1/96 scale battlestations guys if you want to do a combat sub. That scale should be far easier to work with then 1/144, as far as making an interesting operational combat sub.