What you do is....
1. Uninstall Silent Hunter III completely
2. Re-install Silent Hunter III
3. Use Gameshadow to update Silent Hunter III to version 1.4
4. Go to the Subsim link for the GWX mod and download all the files.
5. If you use Silent Hunter III Commander, get the updated config file for that here:
http://gwx.mysite.orange.co.uk/
6. Run the GWX executable file to install GWX 2.0
7. Read the GWX manual and put in whatever mods from the GWX mods list that you want.
8. Get the Torpedo Damage Final mod from here: This mod is a MUST HAVE !
http://hosted.filefront.com/OceanBlue
9. Make a folder in the Silent Hunter III mods folder called "Torpedo Damage" and unzip the file into it.
10. Run the Generic Mod Enabler (JSGME) in your Silent Hunter III folder and activate the torpedo damage mod.
11. All set. Ready to play.