The thirteen-year-old protagonist in the novel. Brian Robeson undergoes a difficult transition when his parents file for divorce. The memories of the divorce, fresh and painful, plague him throughout the book, although less so the more time passes. An incredibly dynamic character, he starts out as a New York City boy who takes for granted the daily conveniences of urban life, and transforms himself into a man of the wilderness, completely self-sufficient and very knowledgeable about his surrounding natural environment. His respect and love for nature only grow with time, as does his ability to come to terms with his parents' divorce.
Brian's mother wants to get a divorce from Brian's father, as she is seeing another man, whom Brian does not know, but calls "the man with short blond hair." His mother has no idea that Brian knows about the affair, which he calls "The Secret." She attempts to talk to Brian about his moodiness, but he refuses to tell her that he knows about her affair. She gives the hatchet to Brian when he departs for the Canadian woods, and he senses her vulnerability during this time, as well as her frustration about Brian's lack of communicativeness. Brian resents his mother for her behavior.
Brian's father does not want a divorce from his mother. He is unaware that she is having an affair, and her wish for a divorce perplexes him. At no point in the novel can Brian bring himself to tell his father "The Secret." Brian's father appeared in one of his dreams, giving him hints as to how to start a fire.
Brian's good friend back in New York. Terry was riding his bicycle when Brian saw his mother kiss the strange man. Brian used to play in the park with Terry. He also appeared in one of Brian's dreams, giving him hints as to how to start a fire.
The pilot of the Cessna plane. He is a man in his mid-forties and the only other person on the plane. He is quiet at the beginning of the trip and later on allows Brian to control the board and get the feel for flying. He dies of a heart attack, forcing Brian to attempt to control the plane's descent.
Brian's mother is seeing the man with the short blond hair. Brian feels an intense repulsion at the notion of this man, and hatred sweeps over him every time he thinks about him.
Brian's old English teacher. Mr. Perpich repeatedly insists on the importance of a positive attitude. His message continues to stay with Brian in his times of discouragement.
Brian's uncle. Uncle Carter eats raw eggs in the morning. Having seen his uncle do this, Brian feels he can eat the turtle eggs that he finds.