My suggestions for a lucrative IX patrol are:
1. Go to the patrol grid so that you take your renown.
2. Move on the surface with a speed of 8 knots. This is the optimal speed that will give you a range of about 20,000 Km.
3. Go to far away hunting grounds like Cuba, Curacao, Gulf of Mexico, Newfoundland, Freetown, Cape Town or Rio de Janeiro.
4. Set up as many ambushes as possible to ensure "easy kills". If possible attack on the surface using the deck gun. That maximises your tonnage as you save torpedoes.
5. Try to fire one torpedo per target. If the target does not sink use the deck gun to finish it off (if possible).
6. Finally be pepared for long patrols (60 days or more) and be very very patient.
Good Luck and Good Shooting
