Over 70% of the world (or three-fourths of the surface of Earth, about 139,705,000 square miles) could be found beneath the oceans, arguably the largest livable space on the planet. As far back as 1963, it had already been suggested mankind some day may build cities on the seabeds (some 7 to 8 miles deep at the bottom of the oceans) because of the pressure of growing populations on the continents.
Rather than going off into space and colonizing the Moon and Mars (the planet Jupiter was also hinted), undersea atomic plants could be used to supply some 3000 kilowatts of power and heat for a submarine community of 6000 people. The nuclear power plants would convert heat directly into electricity. It was explained, "If it's colder than (50 degrees Fahrenheit), (man) has to wear heated gloves and suits, which are being developed on the 'electric blanket principle' with wires or circulating warm water tubes."
Oceanographer Harris Stewart Jr. told the 'Associated Press' in 1965, "We are most intrigued by the great potential that the ocean holds for the betterment of mankind. It is man's last great resource on Earth. The time has come to realize that if we are to survive on this Earth, we must first understand the intricate workings of the global sea and the role this great body of water will play in the future of the race." Of food supply, scientists believed the answer was in aquaculture.
The sea (or water) sustained all living things on Earth from plants to fish and animals. It was pointed out, "From the sea came the continents. The whole Earth was once a sea. The continents are but transitory islands in a lasting sea. The sea forever encroaches on the shore." Over 50 million years ago, the Himalaya mountains were said to be sitting on the ocean floor. Winds, tides, currents, waves and rains all came from the sea. It was understood, "Hurricanes play a vital part in maintaining the heat balance between the tropics and polar regions."
Richard Cunningham of Westinghouse told 'United Press International' in 1963, "If man could establish an undersea community as a base for geological studies or mining operations, it would be comparable to discovering a new world. But like outer space exploration, undersea work would require that man bring his environment with him. And, like space flight, this would require large amounts of power to sustain life in such an environment. The undersea atomic plant would be 46 feet high and 20 feet in diameter. The Navy-Westinghouse study indicates (at the time) it could operate unattended at full power for 18 months and at reduced power levels for at least 6 more months."
"Water is heavy." Hence at sea level (some 7 miles of water), a person's movement would be restricted and he or she must withstand roughly 4000 pounds of high pressure the human body was not designed to endure. Toward the end of the 20th century, "a lot of underwater exploration is done by robots, or ROVs (remotely operated vehicles)." Although oxygen could be found in the oceans, the oxygen dissolved in the water hence permeable membranes would need to be developed to "draw breatheable oxygen from the water" because the human's lung was not designed to collect oxygen from water.
Deep beneath the sea would be dark. B.G. Andersen of General Dynamics Corp. told a marine systems conference in 1966 held in Los Angeles and sponsored by the American Institute of Aeronautics and Astronautics and by the U.S. Navy, "For instance, a color we call 'international orange', a glaring, fluorescent yellow-orange, has been considered the most visible color under water. It has been found that although international orange is easier to see than any other color in shallow water, it disappears when there is no ambient light from the surface. Thus in deep water, say at 200 feet or below, the color that can be seen best is black."
Since 1977, scientists reportedly uncovered life around underwater "hydrothermal vents" that gushed up hot water through small "smokestacks" on the ocean floor. Mineral deposits such as copper and iron-and-manganese-rich sulphides and nickel, cobalt could be found on the ocean floor. Once the mines on the continents had been depleted of its minerals, it was reasoned man would need to start mining in the sea. Oil, natural gas, diamonds were said could be found beneath the sea. Geologists had also discovered that the sea floor stretched from places called mid-ocean ridges at the rate of 1 inch every year. Molten rock pushed up from beneath the crust and cooled to form a new ocean floor (hence Europe and Africa had been getting farther away all the time).
Alto Blaskeslee of the 'Associated Press' reported in June 1957, "Gravity varies with the shape of the Earth and the structure of its crust. Scientific findings show that the rock under the ocean floor is much different from the basement rock of the continents on which we live. Earthquakes shake the underwater world, sometimes with cataclysmic force. Sometimes they create great landslides of sediment, flowing rivers of mud which may help carve out some of the gorges furrowing the ocean bed. Both seismic and gravity measurements can help piece together the story of the forces that formed great canyons and trenches and mountains."