A year after Liah has lived the adventure of her life be rescuing her mother Clarissa and finding out she is the Princess of the mermaid kingdom the girl has decided to continue with her life as a surfer in Malibu, just like any other young girl, only that Liah could visit her mother underwater any time she wants.
Thanks to her incredible ability as a surfer Liah has been able to get into a very important competition and she wins it, now she has to go to Australia to compete.
Liah is very nervous but knows she can win and of course she does defeating one of her biggest rivals Kylie Morgan.
Kylie just like Liah is a great surfer and is going to compete in Australia. Liah is very excited so she decides to visit her mother and tell her the good news!
Her mother is very busy preparing for a celebration that she wants Liah to go with her, but unfortunately the surfing contest is the same day, they argue about the decision they have to make.
Liah decides to go to the competition and achieves one of her best performances, while doing an extremely difficult maneuver on her board, all of the press notices her.
Georgie Major a sponcer asks Liah to be a model for his brand Wave crest; she is thrilled and accepts to do a photoshoot, they ask her to take her necklace off because it doesn’t match with what she is wearing.
Kylie is at the beach, she meets a fish named Aistar that tells her to steel Liahs magical necklace, so that she can use its powers to win the competition.
Kylie steels the necklace and puts it on, she fallow Amstar’s instructions so she turns into a mermaid and goes underwater, where she finds the evil Eris still captive in her cell. Aistar tell Kylie she can ask Eris for anything she wants and she will give it to her.
Kylie falls for the trap and Eris changes places with her leaving Kylie in the whirlpool cell.
Poor Kylie is now trapped and Eris is now free and swears to get revenge from her sister Clarissa and her niece Liah. Liah is desperate since she can’t find her necklace, so she goes under water to look for it. During her search she finds Kylie trapped in the whirlpool cell and she helps her get out, she forgives her and they become friends.
Eris and Aistar travel to the Tide Ceremony so that Eris can receive the power to create Mirilia and with it finally rule the entire ocean, Liah arrives just on time to stop Eris from taking over the kingdom.
Leah returns to the surface and compete against Kylie, but this time Kylies her new friend wins.
She is happy for Kylies victory as if it where her own!