Flipper goes to Bud and Porter Ricks for detective help after seeing a treasure chest stolen from the wreck of a sunken Spanish ship hidden on a nearby island.

Flipper disappears for several days and, when found by Porter Ricks, Sandy and Bud, is with another dolphin, an amazing albino the only white dolphin in Porter's memory.

While Sandy and Bud prepare for the annual Coral Key Park swimming race, Porter is overcome by toxic chemicals dropped from a passing ship while he is carrying out an underwater investigation.

Bud trying to help an injured man and his wife marooned on a sailboat, has to call desperately for help from Flipper when the boat becomes caught in treacherous coral reefs.