Job done
Not quite the slaughter I had anticipated though. I had imagined myself knocking off the remaining destroyer, using one torp per merchant and generally cruising up and down the columns finishing them off. Not to be however for a number of reasons.
Firstly that last escort was a slippery customer. Fired an eel at him and missed, after that we reached an accomodation. He took up station at the rear of the convoy and didn't bother me so I didnt try to sink him.
Secondly the weather turned really crappy so I would not have been able to use my deckgun had I tried and thirdly I noticed that the merchants were now armed so cruising on the surface in the middle of the convoy was plainly not a good idea.
It was a turkey shoot really. The hardest part was regaining contact in the fog, lots of diving to get sound checks. They never altered their mean course after all the zigzags. The escort never stood a chance of catching me from the back of the convoy. I was long gone from position by the time he arrived.
Final tally 1 whale factory,2 medium tankers, 2 medium cargoes, 1 large merchant and 3 destroyers for 59000 tons. I'm happy with that