X Marks the Spot is an object in the Shipwrecked DLC that appears only after its location has been revealed by reading a Message in a Bottle. It appears as two X-crossed bones over disturbed soil. It can be dug up with a Shovel or shot with a Boat Cannon to reveal Bone Shards and a Chest containing several pieces of treasure. There is a 1% chance for a Booty Bag to spawn as well.
There are fixed presets of the treasure chest loot, mixed with some random loot plus some chance loot.
One of these items is always added to the treasure chest, based on a weight list (the higher the number, the higher the chance of appearance).
Each item in this loot table has its own chance of appearing, or not. So it is possible to get every item or none.
Standard Random Loot:
Most Random Loot outcomes have the same Loot Table, all equally weighted (1):
Standard Chance Loot:
Most Chance Loot outcomes have the same Loot Table: (25%)(25%)(10%)