Yes that's the one, thanks.
I've just been playing as a British Sub, I created the mission then altered the side/Nationality in the scripted file in SingleMissions.
I tried it against a German armed trawler, I let him spot me then he got closer and began firing. I dove and fed him a fish but he evaded, in fact he evaded all 3 of my torp's, I was using a IID type,
I eventually crept away, good job he didn't have DC's