"For those of you who think the rollerskating idea is horrible (which is most of you--myself included), how do you think they should create the underwater effect?"
I think they should use a bunch of different techniques depending on the moment. For example, in the first scene at the concert some of the key characters could do the air-suspension thing (ie- Triton, the sisters etc...) while the ensamble is rollar-skating around on the ground to watch the show. Ariel could make her entrance 'swimming' over the audience in the Mary Poppins way....if thats possible....and for other moments, more dramatic moments Ariel could switch to roller skates so she'd be more grounded. Pun intended. And lets not omit the classic mermaid sitting on a rock costume.
Canadians are not afraid of the dark! Ok...we don't love it, but who does?