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This Australian TV show aired from 1994 to 1998 and was one of my favorites. It was about a girl, Neri, and her sister, Mera, who both grew up on Earth but were from another planet. They can telepathically talk to whales and don't need scuba gear when they swim in the ocean. The TV show starred Marzena Godecki and Lauren Hewitt, as well as David Hoflin, Jeffrey Walker, Kerry Armstrong, Liz Burch, Alex Pinder, and Nicholas Bell. As I love sci-fi, it really intrigued me. I just wish they aired it in reruns.