Hiding Deep Under

Meet Grace Collen. A girl who has her whole life planned out.
But, when she has to return to California, all of her planning goes down the rabbit whole. She never thought that one day she'd become a mermaid. Arriving at Eastcoast High School, she covers up her feelings with a smile, no one could tell she's unhappy.

Will she ever find the real reason she became a mermaid?
Will everyone find out? Will she keep her secret?

You'll have to read the book to find out.