Dove Delta contains a number of small sand islands surrounded by water. The islands have a number of "loose dirt mounds", which can be dug up with the use of a shovel by using the action button. The islands are generally inhabited by swampfolk.
A holotape, titled "For Ozwaldo," is lying on an island with a single tree directly southwest of the small dock, just beyond the outstretched right hand of a skeleton (presumably Ozwaldo) along with his shovel. The note explains where to dig - "on the island with a single tree." There are actually two such islands: the one on which the note is found (albeit the bush could have been included in the count) and another directly south of it. On the southern of these islands lies the treasure.
xbox360 Sometimes, the player can't dig into the mounds with the shovel. [verified]
pcps3xbox360 Sometimes, when trying to dig while jumping or running, the player will fall as if knocked down. You will however stand up when the digging is complete. [verified]
pcxbox360 If you are attacked while digging, your character may freeze, and you will be unable to move or fight at all. On the pc, you may fall as if knocked down. After about 5–10 seconds, you are able get up and fight back. [verified]