Another 'lurker; gives the order to surface! Welcome aboard Muley
It seems you already know one of the best submarine tactics, if you have been shadowing us all for a while, eh?
In addition to the DW forum, I presume you know this site for Dangerous Waters stuff:
http://www.subguru.com/
If you want older US sub tactics, there's plenty of info on this forum, or you could try the real thing here:
http://www.history.navy.mil/library/...b_doctrine.htm
Enjoy - Chock