Slightly west of Gibralter, just sit off the point while submerged and listen for the C3s to arrive. So far I have killed three. Each with one torpedo at 4m depth and impact trigger. They blow up with white flames as if they're carrying something explosive .
I'm having so much fun.
I left Brest for some patrol area in CF?? where I found almost nothing. I decided to hang out near gibralter and it's really paying off. I'll post some pics of where I'm at and what I've sunk when I get home from work (in the next couple of days).
56% realism, VIIC, no mods.