Emma, Rikki and Cleo, three teenagers, found themselves marooned on an island after their boat runs out of fuel. The boat they took from a rich brat trying to pull a prank on Cleo. While on the island, they try to reach higher ground to get a cell phone signal, but Cleo falls down into a cavern. The two girls soon follow in a rescue attempt. They see a connecting pass through water as the only way out, but something magical happens as they all enter the water. Upon exiting on the other side, they get rescued by the harbor patrol. Next day, they find that upon touching the water they turn into mermaids. And not just that, but that they have the power to control the water itself.

Cleo gets caught in the fishing net after trying to expose a poacher working for her dad who's using one of the boats to fish in the protected area of the sea where sea turtles are. Lewis calls the other two mermaids just in time to save Chloe and expose the poacher to her dad. Chloe is starting to accept who she is and what she can do underwater.