H2O: Just Add Water: Cast, Roles, Net Worth, Height, Families, And Relationships

H2O: Just Add Water (2006–2010) is an Australian fantasy teen drama created by Jonathan M. Shiff, produced by Jonathan M. Shiff Productions with Network Ten.

It follows three teenage girls—Cleo, Rikki, and Emma—who become mermaids with water-based powers after a lunar eclipse on Mako Island. The show, a mix of adventure and friendship, ran for three seasons (78 episodes) and reached over 250 million viewers globally, syndicated in 120+ countries.

Filmed on Australia’s Gold Coast, it had a ~AU$18 million (US$12 million) budget, earning revenue through Disney, Nickelodeon, and Netflix.

Main Cast and Their Roles

Phoebe Tonkin as Cleo Sertori

• Role: Cleo, a shy, artistic teen with hydrokinesis (water control), anchors the trio emotionally. Tonkin’s warm, vulnerable performance defined the series; she appeared in all 78 episodes.
• Net Worth: $3 million to $4 million
• Height: 5’8″ (1.72 m)
• Family: Born July 12, 1989, Sydney, Australia, to Nicholas (banker) and Jane Tonkin (film critic). One sister, Abby (actress/model). Attended Queenwood School.
• Relationships: Dated Paul Wesley (2013–2017), Alex Greenwald (2020–2023). Married Bernard Lagrange (art dealer), May 10, 2025.
• Post-Film: Starred in The Vampire Diaries/The Originals (Hayley Marshall), Bloom (2024). Upcoming: Night Shift (2025).

Claire Holt as Emma Gilbert

• Role: Emma, a disciplined swimmer with cryokinesis (ice control), brings structure. Holt’s poised role shone in 52 episodes (seasons 1–2).
• Net Worth: $6 million–$15 million
• Height: 5’5″ (1.65 m)
• Family: Born June 11, 1988, Brisbane, Australia, to Geoffrey (engineer) and Ann Holt. Siblings: Rachael, Madeline (sisters), David (brother).
• Relationships: Married Matt Kaplan (2016–2017), Andrew Joblon (2018–present); two kids, James (2020), Ford (2022).
• Post-Film: Starred in The Vampire Diaries/The Originals (Rebekah Mikaelson), 47 Meters Down (2017). Recent: The Outsider (2025).

Cariba Heine as Rikki Chadwick

• Role: Rikki, a rebellious teen with pyrokinesis (heating water), adds edge. Heine’s fiery performance was iconic; appeared in all 78 episodes.
• Net Worth: $1 million–$2 million
• Height: 5’6″ (1.68 m)
• Family: Born October 1, 1988, Johannesburg, South Africa, to Kevin (musician) and Michelle Heine (ex-showgirl). Brother: Kyle (musician). Moved to Australia at 3.
• Relationships: Dated Jamie Timony (2008–2016), Burgess Abernethy (2006–2009). Married Matt Pong, June 24, 2024; son born early 2025.
• Post-Film: Starred in Blue Water High (2008), Hiding (2015), Infinite Man (2016). Recent: Bump (2023, guest).

Angus McLaren as Lewis McCartney

• Role: Lewis, Cleo’s nerdy best friend and love interest, supports the mermaids with science. McLaren’s earnest charm shone in 65 episodes.
• Net Worth: $2 million to $3 million
• Height: 5’10” (1.78 m)
• Family: Born November 3, 1988, Wonthaggi, Victoria, Australia, to Kerena McLaren. Brothers: Rhett, Aidan. Grew up on a dairy farm.
• Relationships: Dating Anneliese Apps (2017–present).
• Post-Film: Starred in Packed to the Rafters (2008–2013), Doctor Doctor (2017–2021). Upcoming: The Speedway Murders (2025).

Luke Mitchell as Will Benjamin (Season 3)

• Role: Will, a free diver and Bella’s love interest, uncovers mermaid secrets. Mitchell’s adventurous role was in 26 episodes.
• Net Worth: $2 million to $8 million
• Height: 6’1″ (1.85 m)
• Family: Born April 17, 1985, Gold Coast, Australia, to divorced parents. Siblings: Michael, Daniel, Benjamin (brothers), Bree (sister).
• Relationships: Married Rebecca Breeds (co-star, 2013–present); son born February 20, 2025.
• Post-Film: Starred in Home and Away (2009–2013), Agents of S.H.I.E.L.D. (2015–2016), Blindspot (2017–2020). Recent: The Speedway Murders (2024).

Burgess Abernethy as Zane Bennett

• Role: Zane, a rich kid and Rikki’s rival-turned-boyfriend, becomes an ally. Abernethy’s roguish charm was in all 78 episodes.
• Net Worth: $1 million to $1.5 million
• Height: 6’1″ (1.85 m)
• Family: Born February 21, 1987, Gold Coast, Australia, to Shane Denman (architect) and Rosslyn Mary Abernethy (producer/actress).
• Relationships: Dated Cariba Heine (2006–2009), Jordan Loukas (2009). Married Rachel Freeman; two kids (private).
• Post-Film: Starred in William & Kate (2011), Reef Doctors (2013). Recent: Bump (2023, guest).

Ariel Waller as Charlotte Watsford (Season 2)

• Role: Charlotte, a mermaid descendant and temporary villain, stirs drama. Waller’s ambitious role was in 26 episodes.
• Net Worth: $100,000–$1 million
• Height: 5’3″ (1.60 m)
• Family: Born May 16, 1998, Toronto, Canada. Bilingual (English/French); older siblings (private).
• Relationships: Single; no public relationships.
• Post-Film: Starred in Life with Derek (2005–2009), Cinderella Man (2005). Limited roles; pursued education.

Alan David Lee as Don Sertori

• Role: Don, Cleo’s caring mechanic dad, grounds the family. Lee’s warm role was in all 78 episodes.
• Net Worth: $3 million
• Height: 5’10” (1.78 m)
• Family: Born February 24, 1943, Melbourne, Australia. Family private; possibly related to Cleo Massey (Kim Sertori).
• Relationships: Married (spouse private); kids include Cleo Massey (actress)
• Post-Film: Appeared in Neighbours (2010s), The Cowra Breakout (1989). Retired post-2010.

Additional Notes

Salaries: Leads earned ~AU$5,000–$10,000/episode, supporting cast AU$2,000–$7,000. The AU$18 million budget covered Gold Coast shoots, mermaid tails, and Sea World underwater scenes. Netflix/Disney residuals boost earnings.

Casting Insights: Open auditions targeted teens; Tonkin (17) won Cleo after one try. Holt (17) used swimming skills. Heine (17) nailed Rikki’s attitude. McLaren (17) fit the nerd role. Mitchell joined post-Neighbours. Shiff prioritized chemistry, creating a tight-knit cast.

Impact and Legacy: H2O’s 250M+ viewers made it a YA fantasy staple, spawning Mako Mermaids (2013–2016) and an animated series. Fans on X/Reddit love the friendship and effects but critique cast changes (e.g., Holt’s exit). The “No Ordinary Girl” soundtrack went multi-platinum. The show’s feminist themes—agency, teamwork—endure, though some note simplistic romance arcs. Streaming on Netflix keeps it relevant.

Post-Film Careers: Tonkin and Holt hit U.S. fame (Vampire Diaries). Heine and McLaren stayed in Australian TV. Mitchell broke into U.S. action. Abernethy and Waller slowed down; Lee retired.

Cultural Influence: H2O shaped mermaid lore in teen TV, with iconic pool transformations and Mako Island. Its “girl power” vibe and hydrokinesis scenes trend on X during fantasy TV discussions, though some critique its light take on supernatural stakes.

Conclusion

H2O: Just Add Water’s cast, led by Tonkin, Holt, and Heine, crafted a beloved fantasy series with global reach. Net worths range from $100,000 (Waller) to $15 million (Holt), reflecting varied careers. Personal lives, from Tonkin’s marriage to Waller’s privacy, add depth. Its enduring popularity, streaming on Netflix, and cultural impact cement its legacy as a teen classic.