Some of my friends sunk a Grade V ship last night and their opponents buried their flag and presumably logged off shortly afterwards. While I understand that this is something that doesn't happen often, I think that there is a reasonable amount of friction that could be added to the map generation process to prevent this. If players want to bury a set of items on an island, they must first go to their quest table and "grab an empty map". This allows them to bury up to 10 items on a single island. If they want to bury more, or bury at another island, they need to return to the ship and grab another empty map.
Upon being sunk, a player will lose their treasure maps (as it currently is implemented) and their empty treasure maps as well.
This added friction prevents players from being able immediately bury their loot after being sunk, but they can continue to bury items after returning to their ship and collecting a new empty map.
