Ocean's Gift (Book 1 of the Ocean's Gift series)

Sirens don’t fall in love with humans. For centuries it has been so… But Sirena is different. She lost her first love to sharks and a storm, cursing the islands that stole him from her. Times have changed and she must swim ashore once more, to the islands she once cursed. Gone are the boats powered by sail and steam...

Everblue

What do you do when your secret crush isn't human? Seventeen-year-old Ashlyn Lanski is tired of her boring, single life. Swimming and spending time with Tatiana, her best friend, are her only sanctuary. The girls plan to leave their drab lakeside town far behind for college, and Ash hopes to finally ditch her longtime...