For Flipper's New Adventure the writers at MGM came together and mixed the plots of The Admirable Crichton and The Desperate Hours and came up with a story that is cute and entertaining, but also for juveniles. I don't think any adults would buy it. A little bit of Bomba the Jungle Boy thrown in as well.
One phone call to his father who was studying to be a Park Ranger after giving up his career as a fisherman from the first Flipper movie might have eased Luke Halpin's concern for his pet. But he hears some folks from the Miami Seaquarium are going to take Flipper and so he runs away and finds a nice island off the Florida coast to live or at least until the Seaquarium folks go away.
Of course if Luke had made that phone call to Brian Kelly playing his father for the first time, he and Flipper would not have been around to help Tom Helmore's family who are stranded on the same island. He's been kidnapped for the use of his boat by three escaped convicts and they strand Helen Cherry and daughters Francesca Annis and Pamela Franklin on the island Luke took refuge on.
Here's where it gets really dumb. These three are fugitives being hunted by law enforcement and they hit upon the brilliant scheme of holding Helmore and family for a getaway insurance. So they go back to that island and take them all save Halpin whom they don't know about. Absolutely brilliant, these clowns would have killed Helmore and kept on going with that cabin cruiser of his in real life. No wonder a kid and a dolphin take them.
A bit unbelievable for adults, strictly for kids is Flipper's New Adventure.