Ocean Girl follows the adventures of Jason and Brett Bates, who move with their mother (a reasearch scientist studying whale song) to an underwater research station near Port Douglas. There, they accidentally meet Neri, a young girl with super-human strength, the ability to breathe underwater, and an affinity for communicating with whales. As the series progresses through four seasons, the Bateses (and the audience) learn more about Neri's arrival on Earth, her home planet, and the ecosystem of their own home planet.
Ocean Girl, one of the earliest productions to come out of Jonathan M. Shiff Productions, is creator Jonathan Shiff's first science-fiction program; his name has subsequently become synonymous with children's science-fiction and fantasy television programs, through such shows as Cybergirl and H2O.
Ocean Girl is ecological science fiction, in that it uses the genre of science fiction to explore the consequences of exploiting Earth's resources. For example, as the program progresses, Dr Dianne Bates (mother of protagonists Jason and Brett) shifts from her early role as cetologist to a more active role as environmental protectionist, in response to the increasing threat of building large underwater constructions in the delicate ecosystem around ORCA. Similarly, season four shows the devastating effects of a 'Red Virus' on the oceans of Neri's home world.