In 2012, the director of H2O will be making a Season 4. Cariba Heine (Rikki) will confirm it on 11th November on Facebook and Twitter. Apparently Emma will return for Season 4 and Bella will still be there. So there will be 4 Mermaids in Season 4. Angus McLaren (Lewis) will probably not be in Season 4 because he is going back to shoot Packed To The Rafters. Luke Mitchell (Will) will also still be there. And when Season 4 is finished, they will talk about making a Season 5 for all the fans and it all depends on how much ratings they get for Season 4.
Stick around for more Season 4 news.