Moby-Dick is a novel that evades categorization. Just as it employs a variety of different styles and tones, Moby-Dick also falls within a number of genres. Firstly, it can be categorized as an adventure novel, with its setting upon the high seas and central chase of the great White Whale filling the novel with the kind of action and drama that typify this genre. Its great length and scope may also qualify it as an epic, with this categorization placing Moby-Dick in appropriate lineage with works such as The Odyssey, which also details the adventures and tragedies of life at sea. In a similar vein, Moby-Dick may also be categorized as a quest novel, with the plot dictated by Ahab’s central quest to enact revenge on Moby Dick.
The episodic nature of Moby-Dick is characteristic of all of these genres, with the overarching hunt for Moby Dick interjected with a series of smaller self-contained episodes that show the scope and variety of life on a 19th-century whaling voyage. Along with this, Moby-Dick also has the essential qualities of a tragedy, as it's hard to deny the bleakness of the symbolically destructive ending, in which everyone but Ishmael drown.
It's also important to note Moby-Dick's potential range beyond the realm of fiction, since it largely presents itself as a sort of history. Ishmael’s obsession with the accumulation of knowledge makes Moby-Dick into a semi-scientific endeavor. Ishmael’s detailing of the measurements of the whale exemplifies this use of the novel as a scientific form of record-keeping. The fact that Ishmael has copied these measurements down in the novel “verbatim from [his] right arm”—where he had them tattooed as “a secure way of preserving such valuable statistics"—highlights how important record-keeping is to him. In turn, the novel itself becomes something of a historical or informational document, or a way to preserve the knowledge Ishmael has accumulated.
