Eric Topp 3rd most succesful U-boot commander commanded type VII:know:
And IIRC Robert Gysae commanded type VII too.

And statistically the third war patrol for U-boot was it's last. But that just an avarage. Many went down on their first.

U-98 Type VIIC

http://uboat.net/boats/u98.htm

what i do is :)
 

I play with others at normal .( BUT) I have changed two thing in MY game # 1 ship sinking time = false # 2 is torpedo lode time = false all other settings are at true . i sink one ship = if luck be with me . I fire , dive at 8k turn as i dive to 100 meters . go to silent run keep diving to 150 meters and turn till i am at 180 meters . NEVER GO BACK TO CONVOY TO ATTACK . IF A SHIP THAT WAS PART OF THE CONVOY IS COMING MY WAY AND THE DDS ARE GOING AWAY AND THERE IS TIME LEFT = 9O MIN TO A GAME I WILL USE THE TWO TORPEDOES THAT ARE LEFT = SUB IS A 7B = ATTACK THE SHIP.

Yes. Uboat.net is my friend too.
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As to normal tonnage.

Even if I have 100% realism, no map contact update, hitman's GUI and several "out of the game" restrictions, still tonnage count is quite high.

1. Patrol 31 393
2. Patrol 6 113
3. Patrol 34 271
4. Patrol 22 714
5. Patrol 18 881
Total 113 372

Avarege 22 674.

5th patrol was almost zero one, but during return trip I encountered two big ships.