I tried Scapa in 39. First patrol in GWX. I play DiD and few destroyers were about. They knew I was there but could not find me. Anyway, it was night/clear. One destroyer went past me at 500m. I was on the surface

. He did not see me. (some say the AI are too good at detection). I don't believe it after getting that close without being detected. Anyway, I ran away. I was not tempting fate after that close encounter.