Luke is a thoughtful, responsible thirteen-year-old sent to the Charting a New Course (CNC) program after a schoolmate hid a firearm in his locker. Faced with a felony conviction and unable to afford a defense attorney, he chooses the month-long sea voyage over a juvenile detention facility. He acts as a natural leader who stands up against unfairness without deliberately antagonizing those in power.

Will is a sandy-haired, freckled teenager enrolled in the CNC program following a physical altercation with his sister that hospitalized them both. He struggles with low self-esteem and harbors deep resentment toward his sister's academic and social achievements. He complains frequently about his situation and mumbles that he should have been an only child.

Lyssa is Will's slightly younger sister, characterized by her angular face and friendly demeanor. She has bright eyes and attempts to embrace the CNC program, making a genuine effort to learn from the captain. Despite her outgoing nature, she has a hot temper when it comes to her brother and brings a strong aptitude for science and engineering to the crew.

Charla is a tall, athletic thirteen-year-old who excels in swimming, diving, and gymnastics. Sent to the CNC program by a doctor, she suffers from psychological burnout caused by her father's intense pressure to use her athletic talents to escape poverty. She remains quiet and initially resents the other adolescents, assuming they come from wealthy backgrounds.

At eleven years old, Ian is the youngest member of the crew. He is timid and homesick, with a deep obsession for television and the Internet. His parents enrolled him in the program to improve his social skills. He avoids interaction but possesses a vast repository of marine and survival facts gleaned from documentaries.

J. J. is the fourteen-year-old son of a famous movie star. Spoiled and accustomed to flaunting his wealth, he treats the CNC program as a mere inconvenience meant to keep his destructive stunts out of the media. He consistently shows a blatant disregard for authority, choosing to brag about his lawyers rather than cooperate with the crew.

Mr. Radford is the first mate on The Phoenix and a seasoned sailor. He is a cruel bully who despises the young crew members and refuses to learn their real names, opting instead for generic, mocking monikers. He actively delights in making the adolescents miserable and demonstrates a complete lack of empathy for their struggles.

Captain Cascadden is the tall, rugged commander of The Phoenix. With a leathery face and years of sailing experience, he provides a steady, reliable presence for the troubled teens. He genuinely cares about the CNC program and treats the adolescents with kindness, though he remains dangerously oblivious to his first mate's abusive behavior.

Dan is J. J. Lane's personal assistant. He is tasked with managing the fallout of the teenager's reckless behavior and ensuring he boards The Phoenix. He exhibits a weary realism regarding J. J.'s destructive actions and offers a stern warning about the potential consequences of the boy's arrogance.

Jonathan is a wealthy, famous movie star and J. J.'s father. He uses his considerable financial resources to clean up his son's legal messes and ultimately pays for J. J. to attend the CNC program, opting to send the boy away rather than deal with his behavior personally.

Reese is a schoolmate of Luke Haggerty. He abuses Luke's trust by hiding a firearm in Luke's school locker. This betrayal leads directly to Luke's felony conviction and placement in the CNC program.