Submarines and Other Underwater Craft

In the deep, dark, hidden world beneath the surfaces of our oceans, submarines glide silently past underwater canyons and huge unexplored mountain ranges. Today's submarines are fast, sleek, and completely modern. Not so with early submarines. The Turtle, a submarine built more than two hundred years ago, was clumsy and slow. Its first and only mission—to attack an enemy warship by drilling a hole in its hull—was far from successful.