Interesting thing about the deck gun from a patrol I just finished.
GWX 1.03 early Nov. `41 S/E BE I'm lined up to slam a large merchant & a liberty. A bloody pass/cargo cuts the path and two fish hit her, she stops but remains afloat. Two other shots for the liberty score. I got a swan looking for me, she's burning. I zoom in on her and she's showing deck gun hits. After a bit the liberty goes down and the swan putters away, U-47 is out of eels. Without the 88 I think to have waisted time with the flak guns. Finished her with 10 or so shots. Also the h-phone has a still contact about 1200m to the North. The map shows a grey sunk ship a bit closer. Being curious I made my way to discover a sitting duck whale-factory.
Free tonnage
She also showed deck gun hits. Oviously the convoy had a run in with a a/i u-boat.
My point is without the 88 I would have been short what 12-13k off a 56k total patrol.