I recommend you get 'Easy sub control keys' by snider. Brilliant tiny mod & works with GWX3 probably earlier versions as well. It will change all your keys so print out the key page.
Just some of the key changes which i could not do without.
C - Return To Course, Surface, Ahead Standard
V - Ahead 1/3, Periscope Depth, Hydrophone Normal Sweep
A - Hard to Port (hold)
D - Hard to Starboard (hold)
The A & D keys you just hold down, when you want to go back to amidships just let go of either key.