Daughter of the Pirate King by Tricia Levenseller

Sent on a mission to retrieve an ancient hidden map—the key to a legendary treasure trove—seventeen-year-old pirate captain Alosa deliberately allows herself to be captured by her enemies, giving her the perfect opportunity to search their ship.

More than a match for the ruthless pirate crew, Alosa has only one thing standing between her and the map: her captor, the unexpectedly clever and unfairly attractive first mate, Riden. But not to worry, for Alosa has a few tricks up her sleeve, and no lone pirate can stop the Daughter of the Pirate King.