The narrator, Charlotte Doyle, is a smart, intense, and somewhat snobbish 13-year-old American daughter of a prominent businessman. Alone for the first time in her life, and nervous about being the only female aboard a sailing ship, Charlotte initially falls under the gentlemanly protection of Captain Jaggery. During the voyage, however, she learns that the captain is a ruthless, lethal taskmaster, and her faith in him collapses. She joins the crew, learns their skills, proves herself to them during the hurricane, and escapes Jaggery’s lethal wrath. Charlotte’s adventure changes her from a spoiled girl into a talented, responsible, and tough-minded young sailor. When she realizes that her father has the same attitudes as Jaggery, she understands that she no longer wants or needs a family that disrespects who she has become.

Old and weather-worn, Zachariah—his name evokes ancient Biblical prophets and kings with similar names—is the ship’s cook and surgeon. A mentor and advisor to the crew, he also becomes Charlotte’s closest friend onboard. He wants to protect her and their friendship: “Miss Doyle is so young! I am so old! Surely there is something similar in that. And you, the sole girl, and I, the one black, are special on this ship” (24).