A couple of days ago, I was sailing around a fort where two galeons where fighting, waiting for one of them to sink so I could get in the fight. While I was doing so, a sloop was doing the same as me, so I slowly went to them. And at the same time we both asked if they wanted to make an alliance.
So we did, and we managed to sink both galeons. After that, we went on the island trying to finish the Fortress, but a galeon kept coming, we sunk it again but one of them managed to get to the island when the Captain died. We were the one sinking the galeon with my friend, and when we got back to the island, they said the ennemy that came on the island might have stole the key. Since they couldn't find it anymore.
So I want back where we sunk them, search around and couldn't find anything, same on the island itself. So for a moment I thought they had the key and were hiding it. But after looking for it, I found it in the most obvious spot, the tower, right in the middle.
When I told them they laughed because they didn't even look here since it was really obvious. Then we opened the vault and made two piles for each crew, trying to share as equally as possible. And we went back to an outpost together to sell the goods.
Just wanted to share my story. In these kind of games, most people are aggressive because they don't want to lose their stuff. Because they probably trusted someone before and it ended up badly. So yeah, there is not much to do about that.