The Treasure Map from Cayman Sound is a two-part collectible in Assassin’s Creed IV: Black Flag. You first grab the map on the island of Cayman Sound, then sail to Petite Caverne to dig up the buried chest it points to. The chest sits inside a hostile smuggler den, so expect a fight before you collect the loot.
Quick answer: Loot the map from the cadaver at 298,311 on the northwestern shore of Cayman Sound, then dig behind the stalagmite at 863,235 in Petite Caverne to open the chest for 3,000 Reales and the Heavy Shot Ultimate Storage Plan.
Cayman Sound treasure map location (298,311)
The map itself is found on the coast of Cayman Sound, not in the water. Head to the northwestern shore of the island and look for a small cluster of debris. The map is on a cadaver lying next to a broken barrel and a crate.
Petite Caverne dig site (863,235)
The buried chest is located in Petite Caverne, at the smuggler den. Petite Caverne is a restricted area, so guards will be patrolling and will attack on sight. Clear or slip past them before you start digging.
Note: The dig point sits at the back of the camp on a small mound of earth. If the prompt doesn’t appear, reposition slightly until you are standing directly on the disturbed soil.
Cayman Sound treasure rewards
Opening the buried chest gives you cash and a ship upgrade plan for the Jackdaw’s heavy shot ammunition. The Heavy Shot Ultimate Storage Plan increases how many heavy shots the ship can carry.
| Reward | Amount |
|---|---|
| Reales | 3,000 |
| Ship plan | Heavy Shot Ultimate Storage Plan |
How to confirm it worked
When the dig succeeds, the chest opens, and the reward pop-up shows 3,000 Reales added to your balance along with the Heavy Shot Ultimate Storage Plan. The plan then becomes available to purchase and install at a ship upgrade menu, and this treasure map is marked as collected in your progress tracker.
If you cannot dig, you are most likely standing slightly off the exact spot behind the stalagmite, or you are still in combat with the smuggler den’s guards. Deal with the enemies and line up on the mound, then the dig prompt will appear.
