While Fluttershy and all her best friends are showing Tempest Shadow around Equestria, they get a message from Skystar, princess of the Seaponies. She’s super bored and wants her pony friends to come down for a visit! Fluttershy is excited to see more of Seaquestria, so she’s off to the ocean for a vacation with her friend! But when she gets under the water — and is turned back into a Seapony — she soon discovers that not everything is smooth sailing. If Fluttershy can’t help clear up the tension, there could be a real battle at the bottom of the sea!