Lopaka is an 11-year-old Polynesian boy who has the power to speak to aquatic creatures, including Flipper. He lives in the island of Illoka.
He wears a red islanders skirt and an arm band, which all males wear in Illoka.
Lopaka is able to talk to the sea creatures, including Flipper. However, he is the inhabitant who must avoid revealing the underwater secret to his tribe. It is revealed that Lopaka was rescued by Flipper as a child. After being rescued, he and Flipper became friends.
- In the show, Lopaka is referred as a "Menehune". "Menehune" refers to a mythical creature who lives in deep forests and hidden valleys on Hawaiian islands.