In this musical special, the Octonauts must find a way to hold back hungry swarms of coral-eating starfish to save a new friend's fragile reef home.
| Actor | Role |
|---|---|
 Simon GreenallCaptain Barnacles (Voice) | Captain Barnacles (Voice) |
 Paul PantingPeso (Voice) | Peso (Voice) |
 Jo WyattTweak (Voice) | Tweak (Voice) |
 Keith WickhamShellington/Inkling (Voice) | Shellington/Inkling (Voice) |
| MMichael C. MurphyTurnip (Voice) | Turnip (Voice) |
| RRoss BreenCaptain Barnacles (Singing Voice) | Captain Barnacles (Singing Voice) |
 Rob RackstrawKwazii (Voice) | Kwazii (Voice) |
 Teresa GallagherDashi (Voice) | Dashi (Voice) |