I'm trying to find the details of a TV show that was aired on British Morning Television in the mid to late 1990s.
I vaguely remember it being Australian, but that could simply be due to the number of Australian imports CBBC was fond of airing during the summer holiday.
The central plot was about some kind of underwater habitat where the occupants were studying some form of marine biology, and they all wore uniforms that made them look like Seaworld trainers.
I believe, from the freely available technologies (bathyspheres, advanced submarines) that it could have been set in the future, possibly after some kind of environmental incident.
Either way the protagonists were for some reason forbidden from going ashore, and yet seemed to manage it every episode.
A recurring character was a girl who was some kind of bipedal mermaid, and I think she was a mute... unless that part is just the little mermaid blurring into my memory.
Anyone know what this show was?