The Submarine School is about it, and the User's Manual doesn't even discuss those. Basically, the manual will walk you through a few things, but it is mostly one of those generalized "manuals" that have no details about them...
Big question for anyone wanting to point you at something is for them to know what you are playing. Do you have a Stock install of SH4 aka: Silent Hunter Wolves of the Pacific, and whether or not it is v1,5, which has the Uboat Missions in it. If you have mods activated, which are they, and where do you have your game installed.
In the meantime, be sure and consult Rockin Robbins'
Sub Skipper's Bag of Tricks links, as well as THEBERBSTER's
SH4 <> TUTORIALS <> HOW TO DO IT <> INFO <... links for anything that catches your eye...