Headscratchers / H₂O: Just Add Water

• How did Ms. Chatham know Cleo (really all of them) were mermaids? Is she psychic? When she's first introduced, all she has to do is look at Cleo and then she automatically knows she's a mermaid. And she's always showing up at the most convenient times, i.e when the girl's are affected by the full moon, dealing with Dr. Denman, and so on.
  • She notices Cleo getting water on herself and hurrying to wipe it off with the kind of urgency she'd understand all too well from her days as a mermaid. And as for showing up when the girls need her, all those times are full moons. The first two times are her going out of her way to warn Cleo about what happens at the full moon.
  • Miss Chatham initially only goes to Cleo, knowing her from the marine park, so that's where she looks for her. By the time of "Bad Moon Rising", she's stayed at Emma's house and met her and Rikki, so she knows where the house is and can just drop by and ask to see the girls.

• In one episode, Emma dyes her hair red as a mermaid and it turns back to blonde once she's human. Does this mean that when the girls bathe, they aren't actually getting clean? Or does the same rule not apply to cleanliness?
  • Likely cleanliness is different from the hair dyeing, as we see Cleo taking baths well into Season 2. Obviously it could just be her way of relaxing, but the girls can get injured in human form that still lasts when they're mermaids etc so it's a little different.

• In the season 3 episode where Cleo is accidentally stuck in the bathroom as a mermaid making it seem like she was deliberately trying to make Sam late for work, why didn't she just use the bathroom in her bedroom?
  • Just rewatched the whole series this month and, confused by the same question, I relooked at all the episodes with her bathroom. Both the hall and her room are connected to the bathroom. They show it throughout the series. Even that same S3 episode there’s the scene where she is talking to them through the hallway door which is behind her and you can see her room door on the other side.

• In the episode where Emma gets moonstruck during her Dad's birthday party, how did Byron not see her tail?
  • He's too enthralled by her face and the fact that she was very into him. It's also quite dark out, so the tail might not be as obvious through the water.

• How was Ms. Chatham able to give up her powers permanently if that's only possible every fifty years?
  • It's spelled out by Charlotte that the original trio - Gracie, Julia and Louise (Miss Chatham) - gave up their powers when the planets aligned at the full moon. They were mermaids as teenagers and Season 2 marks fifty years since that happened.

• Where's Rikki's Mom? Did her parents divorce or did she die?
  • It doesn't appear to ever be stated so it could be either. As she's not mentioned, it's possible she left years ago and was never involved in her daughter's life.

• When Sam gets Cleo wet on the beach and Cleo runs off, why didn't any of them try to go after her?
  • Bad writing haha. Her dad has never really shown to care about that stuff, even though the next scene he’s in her room telling her they were all worried and looking for her. They likely did search for her after she never came back, since he said that they were waiting for her for hours, but I guess you could say Sam was thinking Cleo hated her and didn't want to bother her and Don wanted to comfort Sam and that lasted until they felt like she hasn’t returned for a long time. That’s the only thing I can think makes sense story wise.