Join the Royal Mermaid Rescue Crew and their seahorse steeds as they protect and serve beneath the ocean waves! Four keen recruits – Nixie, Lana, Cali and Cascadia – are starting out at the Royal Mermaid training school. If trouble strikes on the water, they must be brave and keep the seas safe. Nixie’s a bit of a rule-breaker. Lana is tongue-tied and shy. Cali is keen to prove herself. Cascadia has a BIG task to complete. As the princesses face different challenges, helped by their trusty seaponies, will they each have what it takes to become rescue mermaids for real?