[Schöneboom]

Guten Tag und Herzlich Wilkommen, looney,

To answer a few of your questions briefly:

I've read that if you modify your boat ("buying" upgrades with renown) before the first patrol, you might not get the renown for that patrol. Better to wait until you return to base.

The Sonarman seems to be going deaf -- maybe from hearing too many wabo explosions. When he says he lost contact, check the hydrophones yourself. It is also important to lower your speed -- you'll both hear better!

The magnetic pistol can give you a 1-shot kill, under good conditions: calm seas, depth set 1 m under target's keel. But you did not mention the year of your campaign -- this can make a big difference in torpedo performance. As for best aiming points on the ship, someone else can tell you more. In general, under & just behind the smokestack is always good -- even if you only kill the engines, your gun crew can practice later (have them shoot at the waterline, always).

Re fuel consumption: I go at 1/3 (Langsamefahrt) almost all the time on the surface. No more fuel worries. Submerged, it's Slow (Kleinefahrt) to make the batteries last all day and to hear better.

Well, back to work. Mach's gut!