
While sailing near the outer edges of the Stellar Basin and the nearby islands, you’ll encounter many wrecks with seemingly similar items. Three of these wrecks contain parts of a treasure map. These are roughly located in and around the coordinates “D3, D4”, “G3, G4”, and “H4, I4”.
BTW! Caught the Aurora Jellyfish yet? Try these tips

Once obtained, these three parts of the Treasure Map can be assembled to locate the Sunken Treasure. When comparing the treasure map to the game map, you’ll see that the area of interest is in the southern region of Stellar Basin, pointing towards coordinates “C3”.

Note that the treasure is not exactly where the map shows an “X”. Look for a floating chest secured by a chain below the surface of the sea near the ‘X’ at the south central edge of C3. Interacting with it yields a Ruby Ring, a Research Part, a Silver Trinket, a Silver Plate, a piece of Refined Metal and a Big Bag of Doubloons.

Many players accidentally discover the Sunken Treasure in the early parts of the game and therefore are unable to interact with it again later. Your boat will have to be equipped with a “Dredge Crane” in order to be able to retrieve the sunken treasure.
Trying to complete rest of the hooded figure side quests? Use this guide.