Peabody was right for the most part, except the distance from the star. The distance should be 50nm from the star. Another thing you can do after you do your 48 hrs is to radio in a status report, you may be given another patrol area depending on how many torpedoes and how much fuel you have left. (i.e. I have heard as few as 6 torpedoes and less than half your fuel).
When you get ready to start installing mods, I would recommend RSRD, ROW, NSM, and either RFB or TM be used.
RSRD - Run Silent Run Deep - reworked Campaign layer
ROW - Reflection on Water - graphic updates
NSM - Natural Sinking Mechanics - reworked sinking characteristics for ships
RFB - Real Fleet Boat - Realism mod - most realistic mod
TM - Trigger Maru - realism mod but with gameplay differences.
Hope this helps some.
