Underwater Exploration

The ocean floor covers nearly 71 percent of the Earth's surface, yet we know more about the sun, moon, and stars than about the depths of the sea. Until recently, the extreme pressure and inability to navigate underwater made deep-sea exploration and the recovery of lost treasure almost impossible. Journey deep beneath the ocean on a quest for adventure, knowledge, and sunken treasure in this exciting look at how seafloor mapping, manned submersibles, and underwater robots are revealing the secrets of the ocean. Includes the recent and unexpected discovery of hydrothermal vents on the seafloor far from volcanic activity and powered by chemical changes.