Hi,
I personally hate the fact that often fleets with only a gunboat and a fullstack are landing on my territory although my fleet that gets passed could normally defeat every fleet of every enemy... In my case I have one northern and one southern fleet to defend both sides of my territory from landing attacks while my troops are fighting at far away frontiers. Every fleet has one L'Ocean class ship, 2 japanese Battleships and the rest are copper-frigates. NO fleet in whole Japan could even destroy one of these ships while engaging them, but surely one single gun boat can get behind my lines and destroy my trade harbors.

My solution: Increasing the action radius of the fleets massively. I mean this red circle that appears around any fleet while selecting them that can't get passed by enemy ships without attacking my fleet.
Does anybody know how to do this?