Episode Name: Metamorphosis
Air date: 7/7/2006
Summary: Three very different teenage girls, Emma, Cleo and Rikki, facing everyday teenage problems. With a twist: they’re mermaids; after discovering a magic place where they are given incredible powers over water that change their lives forever.
Watch or download H2O: Just Add Water – Season 1 Episode 1 – Metamorphosis at below links.