I found very much the same last night, LeeVanSpliff. I had a load of marked contacts in a general area, with a general heading. Both gradually got more accurate as he came nearer until I could nail him down toward the end.
I have to admit, all four fish hit in a very tight area, but this was broad daylight.
Hopefully will get to try out a night attack sometime today, and I'll see how I go on with that. Lack of visibility is going to make my range estimates a bit wild I think. Will have to see.
The manual targetting is the most fun I've had for ages, and I have SubSim to thank for that. I'd never even thought of trying it until I came here.
One thing which bugs me though, and is slightly related: The manual mentions changing the name of marks on the map, and adding comments up to 50+ characters long. Is this possible? Be damned if I can find a way to do it.
Again, thanks for the responses guys. Having a ball here.