I don't care WHAT version you're playing, the pucker factor of being caught on the surface by a BB is... intense.
I remember when I first got SH3 shortly after its release, and I tried the single mission against the 3 BBs and their destroyer escorts (Barham mission(?)). I was feeling suicidal, so I surfaced a decent distance behind the BBs and opened fire with the deck gun.
I kept moving, but there wasn't any return fire for a while. Curious, I ship-cammed over to the BB I was engaging... to arrive just as the broadside she was setting up was let loose.
Uhm, yeah. That was very, very cool. And very, very bad to be at the other end of. They don't even have to hit you. I don't think I stopped run short of McMurdo Sound.