H2O: Just Add Water

H2o logo.png

Created By:
Produced By:
Jonathan M. Shiff
Joanna Werner
Executive Producers:
Jonathan M. Shiff, Kay Ben M'Rad & Julia Adams
Philip Dalkin
Deb Cox
Simon Butters
Joss King
Anthony Morris
Sam Carroll
Max Dann
Chris Anastassiades
Susan MacGillicuddy
Chris Roache
Colin Budds & Jeffrey Walker
Series 1: 2006
Series 2: 2007-2008
Series 3: 2009-2010

H2O: Just Add Water (also known as H2O in Australia) is a AFI & Logie award-winning Australian television series. It first aired on Australia's Channel Ten in 2006, and later on Disney Channel, Nickelodeon and ZDF. The series currently runs on TV in over 120 countries all over the world and has an audience of more than 250 million. The series can be found on Netflix, Amazon Prime Video, and Hulu in the United States. It was also available for viewing on Cartoon Network Video in 2010. H2O: Just Add Water stopped airing new episodes in 2010. Rikki appeared as a mermaid in the new spin off show; Mako: Island of Secrets. An animated version of this show named H2O: Mermaid Adventures has been made.


Main Characters

  • Rikki Chadwick (Cariba Heine) - Rikki's not very outgoing and quite a rebel, but is always there for her friends. Her special power allows her to boil water and anything with water in it; she is later able to control fire and lightning as well. Rikki is present in all three seasons. She also makes a special appearance in the two final episodes in the third season of Mako: Island of Secrets.
  • Emma Gilbert (Claire Holt) - Emma enjoys horse riding, swimming and working at JuiceNet Café, which becomes Rikki's Café in Season 3. Her mermaid powers allow her to freeze anything that contains water, and later to freeze without water. In Season 3, Emma is traveling the world with her family. Emma is in Seasons 1 - 2.
  • Cleo Sertori (Phoebe Tonkin) - Cleo is quite shy and awkward, but a loyal friend. Her mermaid power allows her to mold water into a different shape, and from the second season, to create a strong wind that can reach up to 200 km/h. Cleo appears in all 3 seasons.
  • Lewis McCartney (Angus McLaren) - Lewis has known Cleo since they were 5. He is very clever, and has always helped the girls with their transformation. In Season 3, Lewis goes to America to study science. Lewis is in Seasons 1-2 and in the first half of Season 3. McLaren left to film a television show. He claimed this was to pursue a more mature acting career. However, he returns as a guest star in the finale.
  • Isabella Hartley (Indiana Evans) - Bella is introduced in Season 3. She is a singer and a mermaid since the age of nine, and her power allows her to turn water into jelly and also turn water solid. Bella is introduced in the 3rd season, "instead" of Emma.
  • Will Benjamin (Luke Mitchell) - Will is an attractive young male free-diver who falls in love with Bella. His first trip to Mako Island during the Full Moon leads him to get attacked by a water tentacle, and frightens Will into discovering the secrets behind the Moon Pool. He also knows that the girls are mermaids and helps them throughout their last year of school. Will is in Season 3 only. 

Major Secondary Characters

  • Zane Bennett (Burgess Abernethy) - Zane's the local bad boy. Spoiled, rich, but definitely good looking, he and the girls at first disliked each other. Later, he and Rikki became a couple. After he found out about Rikki being a mermaid, they broke up, but eventually got together. When Will comes to town, Zane gets jealous of him and that leads to him and Rikki breaking up again, and this time definitively. Zane is in seasons 1 - 3.
  • Charlotte Watsford (Brittany Byrnes) - Charlotte is the girls' major enemy in Season 2. Later, she became a mermaid as well, but eventually, at the end of the series, she lost her powers forever. After becoming a mermaid, Charlotte received all of the girls' powers, and became a power hungry mermaid. Charlotte believed she was the only true mermaid, due to the fact that her grandmother, Gracie, was one of the three original mermaids. Charlotte appears in season 2. 
  • Miss Chatham (Christine Amor) - Louise Chatham was one of the three original mermaids. She helped the girls during Season 1.
  • Miriam Kent (Annabelle Stephenson) - Miriam thought of herself as Zane's girlfriend, but, apparently to him, she wasn't. She dislikes the girls, especially Rikki, and is one of the main antagonists in Series 1. Miriam only appears in the first season. 
  • Kim Sertori (Cleo Massey) - Kim is Cleo's annoying little sister. She has come really close to finding out about the girls' secret. Her favorite color is probably pink, since she wears it almost all the time. Kim is in seasons 1 - 3. 
  • Elliot Gilbert (Trent Sullivan) - Elliot is Emma's younger brother. Through the series, he has developed crushes on Kim and Rikki. He's got a strong bond with his sister, and appears in most of the episodes. Elliot appears in seasons 1 and 2, but during season 3 goes on a globe trotting trip with Emma and his parents. 
  • Nate (Jamie Timony) - Nate is Zane's insensitive and quite dumb friend, who seems to enjoy getting himself in trouble. He has a crush on Cleo and later one on Bella. Nate enjoys singing, but sounds terrible. Nate appears in seasons 1 - 3.
  • Sophie Benjamin (Taryn Marler) - Sophie is Will's older sister, and one of the main antagonists of season 3. She is curious about the magical gems of Mako Island and hopes to destroy the Moon Pool in order to drill the cavern and take away the gems to sell for cash. She is a strict trainer for Will's diving. Sophie appears in Season 3. 
  • Linda Denman (Lara Cox) - Dr. Linda Denman is a Marine Biologist who discovers entirely by her devices that the girls are mermaids and then tries to capture them in the moon pool. Linda only appears in season 1, in three episodes. She is the main antagonist of season 1, and supposedly leaves after believing the girls lost their powers during a lunar eclipse. 
  • Tiffany (Alice Hunter) - Tiffany was the mistreated friend of Miriam. She has a secret one sided crush on Lewis. Tiffany is only in season 1. 
  • Byron (Christopher Poree) - Byron was a swimming and surfing champ that Miriam and Emma have a crush on. He dates and eventually is dumped by Emma. Byron is only in Season 1.
  • Donald Sertori (Alan David Lee) - Cleo and Kim's dad. Donald is in seasons 1 - 3.
  • Samantha Sertori (Penni Gray) - Samantha is a geologist. She eventually marries Donald Sertori. Sam is only in season 3.
  • Ash (Craig Horner) - Ash is a horseman and begins to work at the JuiceNet Cafe, where he meets Emma and falls in love with her. At first they have a rocky start, but later begin to become good friends and even boyfriend and girlfriend. Ash appears in Season 2, but is absent for Season 3, most likely due to Emma's own absence.
  • Neil Gilbert (Jared Robinsen) - Neil is Emma and Elliot's dad. He works as a business man, for Harrison Bennett. Neil is in seasons 1 and 2, then goes on a family trip around the world.
  • Lisa Gilbert (Caroline Kennison) - Lisa is Emma and Elliot's mom. She is a certified junior lifeguard. Lisa is in seasons 1 and 2, then goes on a family trip around the world.
  • Wilfred (Ariu Lang Sio) - Wilfred is the owner of the JuiceNet Cafe. Wilfred is in seasons 1 and 2, but does not appear in season 3 after the JuiceNet Cafe is closed down and transformed into Rikki's Cafe.
  • Harrison Bennett (Joss McWilliam) - Harrison is Zane Bennett's dad. He is extremely rich and Harrison is only in season 1.
  • Ms. Taylor (Mouche Phillips) - Ms.Taylor is Lewis and Cleo's Science teacher. She is only in season 3.
  • Ryan Tate (Andrew Lees) - Ryan Tate is Samantha Sertori's co-worker and a geologist.
  • Bev Sertori (Deborah Coulls) - Bev Sertori is the mother of Cleo and Kim, and ex-wife of Don Sertori. In season 2, it is explained that Bev divorced her husband, and the strain of her absence causes stress between the girls and their father.
  • Annette Watsford (Tiffany Lamb) - Annette Watsford is the mother of Charlotte and daughter of Gracie. She helps explain some things about Gracie's past to Charlotte. Annette only appears in season 2.
  • Amber (Rebekah Madden-Fisher) - Amber is one of Emma's friends. She only appears three times during Season 2.
  • Max Hamilton (Martin Vaughan) - Max Hamilton is the former boyfriend of Gracie, and knew about her, Julie, and Louise's powers. Fifty years before the events of season 2, Max did research on planetary alignments. Him and Lewis become friends, and Max learns about Emma, Cleo, and Rikki's secret. He donates his research to Lewis, but also tells Charlotte about her grandmother, and helps explain to Charlotte how to become a mermaid. Max later helps Lewis by telling him about the planetary alignment that will remove a mermaid of her powers, and the girls use this to remove Charlotte of all her powers. Max appears in season 2 only.
  • Laurie (Matthew O'Kine) - Laurie is one of the workers at the Sea World Marine Park. He is good friend of Cleo and Lewis. He appears only in the second and in the third season.
  • Mrs. Geddes (Andrea Moor) - Mrs. Geddes is the manager of Sea World Marine Park, also she is relatively strict with her workers even Cleo. She appears in one episode of Season one and one episode of season two.

Seasons Summaries

Season 1

Emma, Cleo and Rikki in their mermaid form.

The first series revolves around Emma Gilbert, Cleo Sertori and Rikki Chadwick, who are given the power to turn into mermaids. They discover their amazing powers over water - Cleo can control the shape and volume of water, Emma can freeze it, and Rikki can boil it. Lewis McCartney, a friend of Cleo - and later of the three of them, helps them from being exposed. These series is mostly about Rikki, Emma and Cleo learning to use their powers and dealing with everyday problems, such as pesky siblings. Cleo meets an old lady, Louise Chatham, who was a mermaid in her past and who warns her, Emma and Rikki from the full moon. Zane Bennett is trapped at Louise's sinking boat and Emma has to save him. Zane sees a half of her tail and looks everywhere near Mako Island for the "sea monster". Zane sees Emma as a mermaid, but he didn't recognize her because she had red hair. Rikki and Zane become a couple. At the end of the season, Zane helps Dr. Denman capture the mermaids. Zane finds out who the mermaids really are and he rescues them with Lewis' help. During the lunar eclipse, the girls lose their powers, only for twelve hours, but it was enough for Dr. Denman to lose interest in them.

Season 2

Charlotte, Rikki, Cleo and Emma, in their human form.

A full moon in conjunction with a rare planetary alignment calls the girls to the moon pool at Mako Island where their powers and abilities are greatly augmented and strengthened to higher power levels. The second season revolves around the arrival of a new girl, Charlotte Watsford, who has just moved to the neighborhood and who, since from the start, develops an attraction for Lewis. After Charlotte sees a film of her grandmother Gracie as a mermaid she meets Max Hamilton who was once romantically involved with Gracie. Happy to have met his lover's granddaughter he tells her about the previous mermaids and of Mako Island. Charlotte travels to the moon pool during a full moon and becomes the fourth mermaid in possession of all the girls' powers and abilities. Believing herself superior as the one "true mermaid" she and the girls become sworn enemies. This conflict results in a confrontation, during an especially strong and powerful full moon, which ends with Charlotte being permanently stripped of her mermaid powers, abilities, and mermaid form. The girls also have romantic entanglements. Cleo breaks up with Lewis for being too clingy and protective after which he dates Charlotte. Rikki and Zane start dating again after breaking up during the series one finale. Emma meets Ash and flirts, but the guy is frustrated by all the secrets that she is constantly hiding. Eventually Emma confesses to him be a mermaid. Meanwhile, Lewis, is sad because of the conflict between her friends and Charlotte, but in the end he comes to the conclusion that his loyalty is to girls, and in particular to Cleo. Lewis decides to break-up with Charlotte and to resume his relationship with Cleo.

Season 3

Rikki, Cleo and their new friend Bella, in their mermaid form.

It's nearly the end of the summer holidays and Cleo and Rikki are about to face their last year of high school without Emma, who has gone overseas. Together with Lewis, they're confident they know everything there is to know about Mako Island. But when water attacks the girls on a full moon, they realize a new, potentially dangerous force is developing on the mysterious island, and Will, a boy with freakish free-diving skills who stumbles upon the Moon Pool could hold the key to understanding the powerful energy...

Thankfully they find an ally in Bella, a new girl in town who reveals an equally surprising twist: she too is a mermaid with extraordinary super powers. Together, the new trio face phenomenal challenges as they discover the dark secrets of Mako Island and realize their destiny as mermaids.

H2O: Just Add Water: The Movie

This TV movie summarized the events of the beginning of series one, superimposing the episodes: "Metamorphosis", "Pool Party", "Catch of the Day", "Party Girls", "Lovesick", "The Denman Affair" and "The Siren Effect".

H2O: Metamorphosis

In the United States "Metamorphosis" and "Pool Party" premiered as a one hour movie.

H2O: Exposed

In the United States "Dr. Danger" and "A Twist in the Tail" premiered as a one hour movie called "Exposed".

H2O: Just Add Water: And Then There Were Four

In some countries, such as Hungary, Romania and Bulgaria, the episodes "The Gracie Code, Part One", "The Gracie Code, Part Two" and "And Then There Were Four" are combined into a 70 minute television movie. This version aired only in central and eastern Europe on Jetix.

H2O: Just Add Water: The Finale

In some countries, such as Hungary, Romania and Bulgaria, the episodes "Three's Company", "Sea Change and "Unfathomable" are combined into a 70 minute television movie. This version aired only in central and eastern Europe on Jetix.

Awards and Nominations


  • 2007 Logie Award for "Most Outstanding Children's Program"
  • 2007 Nickelodeon UK Kids' Choice Award for "Best TV Show"
  • 2008 Logie Award for "Most Outstanding Children's Program"


  • 2008 Nickelodeon Australia Kids' Choice Award for "Best TV Drama Show"
  • 2009 Logie Award for "Most Outstanding Children's Program"


  • After the release of series 3 in 2009, we now know that there are other places in the world to become a mermaid, not just Mako Island. Other known places are the Sea Caves of Ireland and presumably somewhere off the coast of China.


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