Daughter of the Deep

Ana Dakkar is a freshman at Harding-Pencroft Academy, a five-year high school that graduates the best marine scientists, naval warriors, navigators, and underwater explorers in the world. Ana's parents died while on a scientific expedition two years ago, and the only family she's got left is her older brother, Dev, also a student at HP. Ana's freshman year culminates with the class's weekend trial at sea, the details of which have been kept secret. She only hopes she has what it'll take to succeed. All her worries are blown out of the water when, on the bus ride to the ship, Ana and her schoolmates witness a terrible tragedy that will change the trajectory of their lives.
But wait, there's more. The professor accompanying them informs Ana that their rival school, Land Institute, and Harding-Pencroft have been fighting a cold war for a hundred and fifty years. Now that cold war has been turned up to a full broil, and the freshmen are in danger of becoming fish food. In a race against deadly enemies, Ana will make amazing friends and astounding discoveries about her heritage as she puts her leadership skills to the test for the first time.
"Did you know more than eighty percent of the ocean remains unexplored? EIGHTY, PEOPLE! It is very possible that at this moment a mermaid and a giant squid are munching on macroalgae macaroni and wondering when we’re going to catch up and discover that Atlantis was just a theme park that went terribly wrong. Who knows? No one can say for certain, because so much of the ocean is unknown. And I am terrified of the unknown, so it goes without saying that I am absolutely terrified of the ocean. Perhaps it started when, at the age of ten, I picked up a starfish by one of its arms ... and soon found myself holding a single wiggling appendage. At the time, I didn’t know that starfish arms could regenerate. I believed I was a murderer. I fell to my knees and bellowed with horror. (CURSE YE, FORMIDABLE MIGHT! SUCH INNOCENCE ... DESTROYED! DOES THIS MEAN I CAN PERMANENTLY SKIP GYM?)"