Eight years after her older sister was swept out to sea, eighteen-year-old Ava Adair still swears off the ocean. It takes a promise of the best vacation of her life aboard the Ocean Jewel with her friends to get her even within reach of the waves. When she steps aboard the luxury yacht to sail the California coastline, the last thing she expects is to gain the attention of gorgeous Carter Stevens, the yacht's deckhand, who becomes the perfect distraction against her fear of the open water.

On the yacht, a freak accident involving Carter reveals a secret he's been hiding from Ava. She discovers that he's a merman and by saving her, he changed her life. One misstep could reveal the new secret they share and ruin the life on land she's desperate to maintain. Torn between a future on land with her family and a new life at sea, Ava must decide--is her former life worth fighting for, or can she accept that she belongs to the ocean?