Under the rules as I’ve posted it is three moves. But why on earth would you be underwater in the s Black Sea?? Everyone would know you’re there.
You can only surface where you are, so it would be F Black Sea Surface. F Black Sea Move Constantinople. F Constantinople Dive Aegean Sea.
If you were already at the surface in the a Black Sea you wouldn’t need the first move, to surface.
If a lot of people don’t like the rule, we can try and change it, maybe to allow Underwater in certain land/sea spaces?