Glad you got it working! Now, go sink something!
Ooooooo, not sure on that one. I don't use modern boats.
But if memory serves, I don't think anyone has modeled a modern sub interior. But I could be wrong.
You can try a forum search in the SH4 Mods Forum. That would be your best bet. Or possibly look at the modern boats thread.
Worst case, post a question as a separate thread.