A boat is boarded by "pirates" who rob the people on board and sink the boat. Meanwhile as Keith looks for a missing pod of dolphins, he comes across the salvage mission for the sunken boat , led by Carl Grimes. Keith is concerned that the equipment noise is driving away the marine life in the area.
     Later Grimes meets with the boat's owner and we find out the "sinking" was all a plan to be able to recover a treasure that was found in that area. After a disagreement, Grimes kills his boss and resumes bringing up the treasure at the site.
     Meanwhile , Flipper finds and gives Mike and Maya a gold medallion. They bring it to a local shop and get $500 for it. Mike buys a brand new windsurfer with the money and Pam becomes suspicious.
     After learning of the medallion Keith learns that it was part of a treasure from an old Spanish ship the "Esperansa" , and that the medallion is really worth thousands.
     At night, Mike and Maya decide to dive to find more of the treasure but are found and kidnapped by Grimes. When Flipper comes to their aid he is injured.
     When a wounded Flipper shows up at the research center, it is realized that the kids are missing. Then Grimes calls and tells Keith that If he is left alone to finish bringing up "his" treasure, the kids will not be harmed.
     Keith and Pam head off to save the kids. Keith sneaks onto the salvage boat and helps get Mike and Maya to safety. After a struggle, Grimes is captured when the marine police show up.

Flipper scenes, characters, and logos are a trademark of SGM Productions in association with Tribune Entertainment Last Modified: March 25, 1998