If you like geometry you might like to read the United States Navy Maneuvering Board Manual from 1941. You can download it from:
http://archive.org/details/maneuveringboard00unit
Pages 22 - 23 are the most important. The methods described in the manual are usable in SH3.
One can even use these methods with hydrophone bearings, but it is very time consuming and basically cheating, because real life hydrophones weren't as accurate as these simulation hydrophones.
If this approach feels too theoretical, you might want to try Hitman's Kriegsmarine whizz-wheel, which is great fun too.