The standing figure with the boat hook bears a strong resemblance to traditional depictions of Saint Michael or Saint George, whose heroic defeat of a dragon parallels this New World struggle.  
 
John Singleton Copley, Watson and the Shark, 1778. National Gallery of Art, Ferdinand Lammot Belin Fund 1963.6.1 Right: Raphael, Saint George and the Dragon (detail). National Gallery of Art, Andrew W. Mellon Collection 1937.1.26