As a full grown adult at the time I used to watch this series on The Disney Channel on long, boring Sunday mornings when there was nothing else on TV. Occasionally I would tape episodes when there was a good discussion on the Sunday morning political shows and watch the episode later. To all of you who were children at the time and remember it, I wish to reassure you that there were many different references in the stories to things that really were more on an adult level. It wasn't all in your head. The series pretty much held up at an adult level. Unfortunately, the show was made in Australia so it didn't attract much attention in the United States. There was an underlying message of environmentalism and taking care of our planet in addition to the references to mermaids and the general remaking E.T.:The Extra Terrestrial story lines that were common in the 15 years after Steven Spielberg's groundbreaking film.
The series only lasted three years. In year one we were introduced to the Ocean Girl Character. In year two, it was discovered that she had a sister who had been adopted by a human family and was then taken back to the island by the Ocean Girl. In year three, it is discovered that there is a spaceship buried under the island, inside of which is a boy who knows nothing about how things work on Earth. The boy is the key to turning on the spaceship, which sends a distress signal, that brings a ship from the Ocean Girl's home planet and takes the ocean dwelling aliens back home. As far as I know, this is how it came to an end. If there was anything more, only someone from Australia would know.
The series only lasted three years. In year one we were introduced to the Ocean Girl Character. In year two, it was discovered that she had a sister who had been adopted by a human family and was then taken back to the island by the Ocean Girl. In year three, it is discovered that there is a spaceship buried under the island, inside of which is a boy who knows nothing about how things work on Earth. The boy is the key to turning on the spaceship, which sends a distress signal, that brings a ship from the Ocean Girl's home planet and takes the ocean dwelling aliens back home. As far as I know, this is how it came to an end. If there was anything more, only someone from Australia would know.