Swan: Water Princess (The Majestics #5)

The ice caps melted and humans evolved to live in an underwater world called Atlacam. At school, Swan gets a perfect score on an aptitude test, which means she’s next in line to rule Atlacam. Captain Queen Bowron hears of this and secretly sets Swan up to be taken away by pirateers.

After being kidnapped by Pinkbeard and her pirateer crew, Swan, along with her plush seal friend, Mono, navigate through high water adventures and learns what makes a true quarter master princess.