Good points, and training and experience will tell. I do want to comment on your last statement, though.

Convoys went out of their way to be unpredictable, making legs different lengths and changing speed as well. I've read more than one report of a submarine setting up an attack only to have the targets turn away at the worst possible moment, and a few involving the captain being disappointed at not being able to get into position and then suddenly have the convoy turn right toward him.

You just never know...

I totaly agree. What my entire point is, in all my posts, is that the basic skill of jotting down a plot with data givin on a piece of paper is, well, a piece off cake. And should take no effort at all.

I try to be very specific. Off course, if a target is acting totaly unpredictable, it's a huge pain in the, err, stern to get an accurate firing solution.

I guess you could summarise my posts by saying: the crew should have no effort at all at perform very basic skills.

If the enemy decides not te be a good sport and doesn't politely sit still until we've shot them, well yeah, that might complicate things a bit. :)