This may be a bit difficult to implement but its an interesting idea none the less.
Dig a hole then place this loot sack over the top. You find these loot sacks like any other resourse. You can bury your loot inside it and it will be buried and hidden.
It will persist even during server merge so long at least 1 crew member is still in the session.
It is a good way to hide your loot until you are ready to cash in.
THERES A CATCH.
Your loot is not as safe as you think.
If you or a member of your crew is killed by another player, they get a treasure map leading to the exact location your loot is hidden.
This will create a mad dash to dig it up before the rival crew does.
It also makes it possible for a chance to get more than what you bargained for when pirating.
Like this idea or not you gotta admit, it would make for some interesting and tense encounters. Also means death has a penalty in a way, exposure to your ill gotten gains.
thoughts?