I don't think so - you can't constrain someone from attacking a fleet for this reason. What if another (allied?) player who couldn't see the army on land drove off the fleet? My feeling is this is a risk you take when attacking an island or a province far away by sea where you have no continguous territories. You can always build a fort to retreat to.
Still think this would be fine.
That's very gracious of you. I think the best option, if you want to give him an out, is to let him replay but simply build a fort there on the island that he can retreat to once defeated.
Bookmarks