The mermaid's tale
(Book)

"Locklyn Adair has never fit in. The legs she inherited as a result of her great-great-grandmother's curse make it impossible for her to belong under the sea. When her niece is also born without a tail, Locklyn is determined to save her from similar rejection by sending her to the only place in the Undersea Realm where legs are acceptable--the Lost Island of Atlantis. Darin Aalto would do anything to protect his family, even spearheading an impossible quest to find treasure that has been lost for over a hundred years. But when his best friend, Locklyn, joins his crew, his ability to keep her safe--and his shot at winning her heart--comes perilously close to being swept away. A family curse, lost treasure, unrequited love, and a race against time intertwine as Locklyn and Darin seek to save their family, their kingdom, and eventually the entire Undersea Realm without losing each other."--Amazon.com