[magic452]

Intercepting: The most important part of the game.
Once you have course and speed extend the course line out about 20 miles and plot a intercept point somewhere on that line. In TMO the contact will change course about every 20 miles, don't know about RFB. You don't know how long they have held their present course so they may change at any time.
If you can't get there in time trail the contact to see where it changes course and go from there. Keep them at about 12+ miles to be safe. Flank speed is most useful here.

Fast moving task forces or troop ships are a different thing, you just have to go with what ever you can, you'll only get one shot at them.
Convoys and singles you can set up a good ambush on your terms.

You need to get well ahead of the target so you have time to get into a good firing position undetected, depending on conditions about 8 or so miles. Go to periscope depth and let them come to you. Set up your boat as you wait, set torpedoes to high speed, contact or influence, set depth at about 15 feet, can change later if necessary. OPEN the outer doors.

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