Flipper discovers some strange equipment on the floor of the ocean and convinces Keith and Pam to follow him to the location. The two scientists are mystified by the set-up; the more so when two thugs tie them up and dump them overboard far offshore. With the help of Flipper, they escape and discover a plot to produce genetically altered pearl oysters that are capable of reproducing at an astounding rate and threatening Florida's coral reefs.
—David Bassler