Verne often works scientific description into the plot, as when Nemo and Aronnax use their knowledge of the tides and the moon to free the Nautilus after it has run aground. But frequently the novel’s suspense is marred by a clutter of scientific details, such as a long listing of fishes or plants according to scientific categories of class, order, genus, and species. Sometimes Aronnax seems to be merely reciting his knowledge as he gazes out the Nautilus’s windows.
Still, Verne’s enthusiastic depiction of science and technology is a major strength of the book. Verne carefully researched existing submarine technology, studying Robert Fulton’s early designs and the plans for Confederate submarines, such as the Hunley, used during the Civil War. To make his descriptions more convincing, Verne interviewed engineers who had helped lay the Atlantic cable about the strange life forms they encountered under the sea. This verisimilitude is what makes Verne’s novel a work of science fiction, rather than fantasy. Verne’s contribution to the genre is such that modern science fiction writers continue to emulate many of his techniques.