Riptide

Maria is the eldest girl in her orphanage with the biggest secret, not even her roommates know about. She is a mermaid. For the past sixteen years, she had been kept separate from the other teenagers, but when her private instructor resigns over summer break, Maria is thrust into the terrifying, nerve-racking world of high school. Not only does she now have to fit in with the everyday teenager, but she has to keep her merform a secret, more than she's ever had to before.