Of Magic and Rum by Carly Spade

When Atlantis throttles Rhode into another place and time, she’s forced to keep her sea nymph identity a secret from unsuspecting mortals. Now fathoms from her realm and threatened by a vicious sea monster, she’ll require a ship to get back home.

The plan is simple: Find a crew. Stow away disguised as a cabin boy. And kill the captain once they reach the Mediterranean Sea. That was the plan. She couldn’t predict how difficult the latter would be as desires blur with needs in a battle for their lives.
Captain Calico Jack Rackham has made a name for himself as a harsh but righteous leader, earning his place at the helm of The Revenge.
Thus far, he’s avoided capture, until a mysterious beauty sneaks onto his ship, ensnaring him with her cunning nature. What starts as a devious plan to use her for his own gain blossoms into mythical discoveries and a journey into territory he never dreamed of crossing—a devotion far deeper than to the sea herself.