Capt. Barnacles, Kwazii, Peso and friends encounter fascinating sea creatures in "The Octonauts and Surfing Snails", "The Octonauts and Red Rock Crabs", "The Octonauts and Coconut Crisis", and "The Octonauts and Enemy Anemones".
| Actor | Role |
|---|---|
 Simon GreenallBarnacles (voice) | Barnacles (voice) |
 Rob RackstrawKwazii (voice) | Kwazii (voice) |
 Paul PantingPeso (voice) | Peso (voice) |
 Keith WickhamProf. Inkling / Dr. Shellington (voice) | Prof. Inkling / Dr. Shellington (voice) |
 Jo WyattTweak (voice) | Tweak (voice) |
 Teresa GallagherDashi (voice) | Dashi (voice) |
| MMichael C. MurphyTunip (voice) | Tunip (voice) |
| RRoss BreenBarnacles (singing voice) | Barnacles (singing voice) |