Captain Quint reminds me of Captain Ahab of "Moby Dick": obsessed with vengeance against sharks as Ahab is against the whale, perceiving the creature as preternatural. Quint's remarks about the "doll eyes" that roll back in the head in such abnormal fashion. Melville, too, alludes to the eyes of the whale as an aberration, for they are situated in the sides of the head, prohibiting the whale from seeing before him. This idiosyncrasy seems to make the whale more like a moving machine, coursing through the seas as though on a deadly, orchestrated path. Likewise, Quint remarks on the predatory, almost planned moves of the shark who strikes his victim, swims away, and returns for the kill. Both Ahab and Quint perceive the two monsters of the sea as almost metaphysical forces.
He is your stereotypical sailor--rough around the edges, crusty, curt, and tough as a $2-dollar steak. He has sailed forever, owns his own boat, and his capable of withstanding the hard life and rugged weather that Mother Nature throws at him while at sea, and he has the scars to prove it. He has lived most of his life alone and away from people, so he has few social graces. He has had many incidents with sharks and other sea creatures and can tell the story behind each mark...if he likes you. He is street-smart and educated by the world itself, so he doesn't hold much stock in the pretty boy, college-educated types. He does what he wants, when he wants, and because he wants to...not because someone told him to do it.