This movie is a guilty pleasure. I give it 4 stars within its genre (teen, fantasy, TV movie). It's about a teen girl who never knew her mother, and after her father dies suddenly, she is thrust back into her mother's life. Her mother lives on an island, and there are strange things going on, bizarre divisions among the island folk. She begins to realize her father kept her from this world, and from her mother, because of the dangers that lurk from certain people, and maybe even from herself. There are mystifying things (beings?), beneath the ocean waves, but are they friend or foe?
I don't want to give too much away. I will say that I have never read the book this is based on, but I liked it well enough that I might now. Also, everyone's main complaint (mine too) is that the ending is left open ended, so that a sequel can be made. I think this needs to be made into a TV series. There are so many great characters in this movie, that a TV series could run on for many seasons. I hope they listen to their fans, and create more!
If you like teen fantasy/horror, then you'll probably like this.