I always try and bag a few destroyers per patrol, to make life easier for my comrades
The best I got, I attacked a small convoy and took out the leading escort as well as some merchants, the rear escort piled straight into the mix with the remaining ships all over the place, and in the confusion the destroyer got boxed into position perfectly about 600m in front of me, stopping to avoid a collison
For second I thought I'd fluffed it as it got going at the last second but thankfully it slammed into the screws and the whole thing went up