1Reported Missing
Clownfish are disappearing from the bay, so the girls spring into action to find out why. A mysterious diver could be the culprit.
2Lapso de Memória
When the stone circle causes Cleo to forget that she can turn into a mermaid, Emma and Rikki scramble to keep her from transforming in public.
3Dia dos Namorados
Lewis promises to tell his Valentine's Day sweetheart, Abby, a big secret; Cleo is jealous and scared that he will give away the girls' mermaid identities.
4Raptado!
The girls and Bobby the dolphin untangle a mystery when Bobby's twin, Robby, is captured by someone in a mysterious speedboat.
5Um Fenômeno Estranho
When her father goes to sea on a mission, Cleo's worries begin to affect her dreams. Her nightmares could be trying to tell her something.
6Handle with Care
Tired of the racket Miriam and Zane are making at their beach party, Bernie leaves his cave giving the Vandals a chance to move right in.
7O Retorno da Sereia Branca
To protect the White Mermaid, the girls guide explorer Stanley Finch to the underwater stone circle, whose magic makes Stanley think he's a pirate.
8Três dias debaixo d'água
When a spell forces Rikki to remain a mermaid until the next full moon, she has to find a way to lie low, and underwater, for three full days.
9Duelo de Robôs
Lewis is thrilled when the university hosts an underwater robot competition, but the girls fret over the safety of their marine friends.
10A Criatura da Baía
Emma's younger brother catches a glimpse of her mermaid tail and thinks he's seen a sea monster, and soon the whole town is in an uproar.
11Conquista Subaquática
The mermaids turn to a cranky giant octopus for help when the Vandals invade the bay with a horde of stinging jellyfish.
12Perigo Iminente
Having played one too many practical jokes, Teddy can't get anyone to believe his warning that an underwater volcano is about to erupt
13Presos
Lewis joins a famous explorer in a high-tech submarine to hunt for a sunken treasure ship, but a mishap strands them at the bottom of the sea.