Treasure map in Dredge

While exploring Star Bay, you will come across one of the parts of the treasure map. There are three of them in total, and they are all scattered in this place.

1. Look for the first part on the western island of Star Bay (on the left on the map), from the side of open water, not the bay. There will be a broken ship. Search him.
2. Look for the second part on the eastern island of Star Bay, again from the outside. And again there will be debris.
3. Finally, on the upper right of the map from Star Bay, there are two islands standing nearby. Find a place to dredge with a golden glow and get a map (maybe you just need to search the wreckage).

In inventory, you can combine this card and then match it with a regular card. The treasure is at the bottom of square C3 (the chest floats underwater and is tied to a chain so it doesn't float up).