@iratoric Oops, I did miswrite that. Artillery has 1 movement as well.
There will already be 8 historical and permanent sea mine zones. I'm mostly concerned about how to represent the Battle of the Atlantic. One idea is that 6 sea zones could each have a 1/6 chance to spawn a German submarine every round. But playing that kind of whack-a-mole game as the Entente sounds frustrating.
The laziest solution is simply giving the Germans an unhistorically large number of submarines in the Atlantic from the beginning.