The novel challenges assumptions about gender that we might make about adventure stories and who can or cannot be in them. The True Confessions of Charlotte Doyle is about a girl, not a boy, aboard a nineteenth-century ship. That could be considered a bit unusual for the genre.
The novel is written primarily for a young adult audience. In that sense, it speaks specifically to themes that will resonate with younger audiences: education, coming of age, and transformation.
The True Confessions of Charlotte Doyle is a Bildungsroman, which is a fancy way of saying a coming-of-age novel, or a novel of education. Though we never see her in an actual classroom, the ship becomes a kind of school for Charlotte. She gains lessons and life experiences that fundamentally change her as a person and aid in her maturation.
Avi's novel is, most importantly, set in a very specific time and place: a boat setting sail from England to America in 1832. As with most historical fiction, the novel makes us of its historical backdrop to emphasize thematic concerns. For more, see our section on "Setting."