The ocean and, in particular, the deep-sea floor offer vast potentials of various minerals: polymetallic nodules, metalliferous sediments of hydrothermal origin, phosphorites, uraniferous mud and mineral sands, as well as oil and gas. It is now established that the manganese nodules of the North Pacific may exceed in nickel, copper and cobalt content all known reserves on land. Covered by several kilometers of water column and in what was once considered a hostile or even deadly environment, they can be turned into resources only with the aid of new techniques and technologies for exploration, mining and processing. Recent developments in acoustics, electronics and materials lead to new exploration equipment and strategies to locate and quantify the minerals on or below the deep ocean floor. Advances in hydraulics and offshore technology indicate ways to mine the ores, and recent results in mineral processing and metallurgy allow one to produce and refine the metals. These technical trends and results occur in certain, most important, settings: ocean space is no longer regarded as a hostile barrier but with ever-increasing awareness as an environment to be thoroughly protected; political trends as evolving from the Third U.N. Law of the Sea Conference influence the technology and are influenced by it; market factors, such as the future demand for nickel, have an important impact. And, above all, mineral recovery is an exercise to satisfy the human mind, curious and adventurous and concerned with this globe's further wellbeing.