21st Century Sub (The Dragon in the Sea)

Orders first: the twenty-first century, the subtug Fenian Ram S1881, eight thousand feet below sea level. Atomic war has left America desperate for oil, the last twenty subtugs sent to pirate it from enemy undersea deposits were lost, and Ensign Johnny Ramsey sails with a saboteur aboard. It was Frank Herbert's first novel, nine years before Dune; Doubleday called it The Dragon in the Sea.