I was chasing a fast moving merchant in a horrible storm. All I had was occasional hydrophone contacts. I couldn't see ANYTHING on the bridge. It was a mess.
Then, in the waves, i spotted it's wake!! I blindly shot a torpedo where I thought it might be based on the wake and heard an explosion! Muhaha!
Finally caught sight of it on fire, it was like 300m away from me. Some how my deck gun crew braved the hurricane and took it down.