hows the map coming along?
I have a suggestion for the sea zones if you are staying with the hexes. I believe you should keep ocean zones as hexes, but sea zones and coastal waters should have drawn out zones like in the official games. This creates a clear image of which zones naval and air bases control over.
An example would be making the sea of japan one sea zone. Split up the Mediterranean, Baltic, Black, Red, etc. seas into non hex zones. Islands are fine in hexes because they are small and able to fit into small zones. But i think continental territories should not have to defend multiple sea zones.
If you create large sea zones around coastal waters this shows the zone of control naval and air bases will have. This will also prevent you from having to split up your navy to prevent an amphibious assault.
Another way to do it without adjusting the map is to create a rule where if your navy is sitting in a naval base. They have control over all adjacent sea zone hexes. OR Battle of the Bulge style. Your ships have a zone of control over adjacent hexes no matter where they are on the map. So if an enemy navy enters an adjacent hex to your navy. The defender can decide to intercept or the attacker can decide to do battle.
To be honest I prefer my first suggestion with the coastal territories being larger. There is no complex rules and less confusing to which sea zone connects to which land territory.
Also these are just suggestions. It is your map you don’t have to listen to me lol