Set in the beauty of the Pacific Northwest, the legend of Swanson Lake is kept by one man and he's not about to surrender it. When Bill's grandsons come for a summer visit, they stumble into a big-time adventure with a giant turtle named Mel. When Bill's neighbor Bailey tries to kidnap Mel in order to feature him in a proposed theme park, the grandsons plot to hide Mel from the neighbor.

Ernest Borgnine
as Grandpa

Julie Hagerty
as Bonnie

Greg Evigan
as Peter

Jack Scalia
as Bailey Silverwood

Bug Hall
as Travis

Josh Paddock
as Roger

Vanessa Evigan
as Susie

Paul Sampson
as Matt Henderson

George Yager
as Sheriff Edgewood

John Green
as Technician