@Amon-Sul:
Germany has a sub in the North Sea and AC with two figters in Baltic
UK has 1 bat and 5 subs in North Atlantic Seazone
is it possible for UK to attack German sub in North Sea with its 2 subs, and then attack German fleet i Baltic with 1 bat and 3 subs
No, you can’t do that for the reasons stated already. But note that the UK subs can sail right through (or rather, under) the German sub in the North Sea to attack the Baltic.
So the UK could attack the Baltic with up to 5 subs (plus air if available) and attack the North Sea sub with the BB (plus any subs not attacking the Baltic, plus air if available).