The summer holidays have just begun, and for Oceana the mermaid it feels like the end of the world when her mother Coralline tells her they're moving house in a few days – all the way across the ocean! Coralline is planning to re-open the former luxury hotel Seventeen Waves. But she's been tricked by a real estate shark: the hotel is completely run-down and needs a full renovation. And the grand opening is meant to be in a few days! So it's a good thing Oceana already has a few ideas about how to help her mother out. Along with Onda the helpful octopus, a shoal of rather dim seahorses and lots of energy, she sets to work.
