Fins by Ashley L. Knight

Morgan James is visiting sunny Florida for two weeks before the school year begins. Right from the start, she realizes there's something strangely odd about the opulent world in which her mother and her new husband live and suddenly she is swept into another world - a world she could never have dreamed of. Follow Morgan's unbelievable journey in this magical tale of people who are something other than what they seem - OR, are they really people at all? From Goodreads.

Morgan is not who she thinks she is. Going on holiday to her mom she finds out she is half mermaid. She also meets the boy she has been dreaming about for years. It is about eternal love, jealousy and wanting power.
As part of one of my challenges this is the third mermaid book I am reading this month and again I have already bought the second book in this series.

This book qualifies for:
Goodreads 2013 Reading Challenge
Serious Readers 2013
Tower Teams Read 2013-2
2013 Ebook Challenge
Beat the Heat Readathon 2013
2013 Paranormal Reading Challenge (mermaid)
NBRC Stuck in a Rut