Strategy for patrol in baltic operations

[Calvin809]

I've been playing with the Sober Mega mod for a few weeks now with real navigation. I understand navigation and can get around the map easily now but I have a few questions.
First, are we only supposed to attack polish shipping during the Baltic campaign at the beginning of the war? Does the sim even take into account what country the ships you attack are from or does anything count?
Second what strategies are the best for finding and getting into a good attack position in the Baltic area of operations. I've tried four bearings but most of the time my target has changed course to maneuver through the narrow areas in the sea between Sweden and Denmark or to get on the right course through Skagerrak. I haven't tried the later campaigns where you get to hunt way out in the deep ocean where the shipping lanes are but I'm guessing 4 bearings works a bit better out there.