In 'Twenty Thousand Leagues Under the Sea', Jules Verne envisions the (then quite-limited) possibilities of submarines for both exploration and military use while exulting in highly dramatic images like an attack by a giant squid. As colorful and imaginative as it is, it was based on a number of real explorers of Verne's time and on the early submarines of Robert Fulton and the French navy. This nineteenth century novel remains very modern, serving as the basis for a number of films.