Ocean Girl

Dianne Bates and her sons Jason and Bret come to the underwater base ORCA for six months. They meet Winston Seth which is Dianne's assistant. Sher is going to study whales. Brett finds the place cool, but Jason donesn't like it. They also meet commander Lucas. At dinner Brett meets his new friends Zoe and Froggy whos real name is Jake Reilly{}. Dianne, Winstorn, Jason and Brett go out with the boat to put a transmitter on the whale. A girl comes up out of the ocean and stops Jason when he is about to shoot the transmitter on the whale, so Dianne has to do it instead. Nobody believes Jason when he tells them about the mermaid.

Jason and Brett eagerly await the return of Neri and Charlie–as does UBRI's Dr. Hellegren who wants to study just one of the returning humpback whales, Charlie. Jason and Brett go to Neri's island to prepare for her return and find a silver pendant inside an unusual flower. When Dr. Hellegren's helicopter crashes into the ocean, Charlie calls to Neri who goes to help him but ends up being taken captive. Neri manages to escape, with a little help from Charlie, but she does so only moments before Hellegren is rescued by Captain Sam Phillips, one of the new arrivals on ORCA. Dianne's research contract is extended another six months by ORCA's new commander, her son however soon proves to be a challenge for the others. Jason and Brett welcome Neri home.

Winston calls Diane and her sons back from their vacation informing them that UBRI has won the contract to construct ORCA City and their plans threaten a nearby fish breading ground. Dianne, as ORCA's new environmental officer, quickly calls a stop to the construction and begins a environmental study of the site. A dive to collect samples sees Jason become trapped under a fallen strut. As a rescue party is assembled, Charlie calls Neri who comes to save Jason as his air is about to run out. Dianne takes her case against UBRI before a tribunal who rule in her favour, stopping UBRI's construction. Dr. Hellegren's plans to destroy the breeding ground are thwarted by Neri. Hellegren warns Jason and Brett not to interfere with him.

Brett and Jason are out testing a new diving suit when Jason encounters a strange bright light while under water, the pair quickly leave and head off to see Neri. Back on ORCA, Winston is puzzled by a magnetic anomaly on his scans of the ocean floor, even more strange is that the anomaly is in the shape of a perfect square. Dianne announces that she is going to pursue the vacant position of ORCA Commander. Jason matches the location of Winston's magnetic anomaly to where he saw the strange lights, Neri is also intrigued by the region prompting a closer investigation of the region. Neri swims out to the sight with Jason and Winston following in the minifin, ORCA's new underwater submarine. What they find surprises everyone—a huge underwater pyramid. Meanwhile, at Praxis headquarters (Preventative Response And eXtraterritorial Intelligence Service), agents Jake Shelby and Elly Hauser are dispatched to Egypt where reports suggest signals from outerspace are being received.