Patrol 15.
I got lucky, I admit.
Orders are to patrol the African coast off Freetown. Passing Gibraltar we spot a convoy - and off we go to intercept. Sea is calm so we spot it 6500 m away. Warship. I order a deck gun attack, kind of risky, but the destroyer goes down before she even knows where the shells were coming from. Another joins and is gunned to the bottom - light hull damage (I assume, no % indicator). A submarine is spotted and promptly sent to the bottom. In the meantime we are approaching the cargos. One gunned down, but then another escort joins. A firefight ensues and she goes down - but we sustain damage. Under control. I think we're done with escorts - we're not! A final one approaches and doesn't even have time to blink. Her hull cracked and down she goes - we sustain machine gun fire only.
Then - surprise! Heavy shells start falling around us. Periscope depth immediately. A Southampton class light cruiser is giving us a welcoming. Two can play that game. Firing two fish, one hit and she's going propellers up, nose into the water. She won't be long. Here I make the mistake (because I want to be sure) and fire one fish at a merchant (which goes down in 2 seconds, must have hit her bad) and two more at the listing and zig-zagging Southampton. All miss - she goes down anyway.
Tally as you can see, it could have been way more if I hadn't expended my torpedoes on the already doomed warship. It's ok though. All this with GWX and 97% realism (I keep the event camera on). As I said, I got lucky. But my crew rules too
