I feeling like I just learned to ride a bike.

For the first time last night I manually used the hydrophones and found my target. I had gotten a contact report of merchant vessel and set my intercept course. About 10km away from where I thought I would intercept I went to periscope depth and started having my sonar guy do a sweep. No sound contact. Being pretty sure that my intercept course was correct I hopped on myself and did a small arc on the bearing where I thought the merchant would be. And sure enough at 348* there was the sound of screws. At first I didn't believe it so I turned up the ambient volume and my speakers to make sure. Definitely screws. Only a small merchant ship but I took him out with one torp. In my giddiness over finding a contact with my own ears I forgot that I had planned to surface and use the deck gun.