A great battle, GoldenRivet!
After a year of sinking helpless tankers in Caribbean sea, I almost forgot the joy (and danger) a convoy attack brings. It all become more challeging, since I'm at the end of '43.
I had a great success against a convoy in September, when I sank 7 ships (around 60000 tons) in 4 consecutive attacks (first one was a failure and the escorts almost got me) during the 3 days.