Soukai Buccaneers!

Rian Lawrence is sixteen, her mother is gone, and her father—an adventurer who crossed the ocean—has been missing long enough that Rian has started thinking of adventuring as the one way she might find him. She leaves the town she has always known and arrives at King's Bridge, where she is almost immediately caught up in a brawl involving pirates. Two paths open: join the ship of a self-centered but chivalrous captain and his unsettling deputy, or sign on with the young naval commanding officer whose pride in his noble rank barely conceals a harder interior. One of these choices leads to the father. Both shape who Rian becomes.