This article is about Karl from H2O: Just Add Water. You may be looking for Karl from Mako: Island of secrets.

Karl Smug

Portrayed By:
Brett Sellwood
First Appearance:
Last Appearance:
Love interest:
Julia † (ex-girlfriend)

Karl was the love of Julia in the 1950s. He is played by Brett Sellwood.


He was much like Zane- handsome rich bad-boy. When Karl expressed his love to Julia, she thought it would be the right time to reveal she's a mermaid to him. Although Gracie and Louise thought it was bad idea. Julia having made up her mind, told Karl her secret. At first Karl was angry and broke up with her, saying that he gave the love letter to her, not to a fish. After several days Karl contacted Julia again and wanted to meet at the pier. Julia was ecstatic and went in her mermaid form, but Karl surprised her and snapped some photos of her, planning to expose her. Luckily, Gracie and Louise also went there just in time, and threw the camera into the water, putting a stop to Karl's plan. He is never seen or mentioned again.



She was Karl's love in the 1950s. Gracie and Louise discovered that Julia was dating Karl, and wanted her to break it off, since she also shared their secret. Julia was sure it was the right time and decided to tell his secret to Karl. He however rejected her coldly. One day, Karl called Julia, and asked her to meet him at the pier in her mermaid form. Gracie and Louise begged her not to go, but she went anyway. With a camera behind his back, Karl snapped a few pictures of Julia in her mermaid form, wanting to display those for the whole world. Fortunately, Gracie and Louise also came, and Louise threw the camera into the sea. Julia was heartbroken for a long time, and ended her relationship with Karl. Karl tried to tell everyone about the girls being mermaids, but people did not believe him. Julia was heartbroken and according to Louise, she never got over the betrayal. It took some time, but life went on, and she re-established her friendship with Gracie and Louise and renewed their secret.