Already been some cool work done on this so far - see this thread:
http://www.subsim.com/radioroom/show...=100840&page=1
I'm using that iced Type VIIC now in the North Atlantic in February '44 - very nice looking indeed
Of course, it could use an even heavier coat of ice on it, and somebody really does need to do some iced-up foul-weather crew clothes to go with it as suggested in that other thread - now that would be truly awesome