This documentary examines the world's seas and oceans, from Australia's tropical Barrier Reef to Alaska's arctic waters. After a brief discussion of the evolutionary development of the earth's waters and the many ways by which people benefit from them, the film explores microscopic marine life. Footage of diatoms and the tiny crustaceans that eat them is followed by shots of colorful hydras. Next, an octopus and shark are shown fighting each other, a bloody battle won by the shark. The film then describes how sharks are captured by Florida's Marineland using tranquilizer-laced bait and revived by professional "shark walkers." Crab herding and Otis Barton's benthascope, a steel underwater chamber that on 16 Aug 1949 descended to a record-breaking depth of 4,500 feet, are depicted. Footage of enormous seismic waves, caused by undersea earthquakes is seen, along with shots of storm-tossed ships and boats. Various dangerous sea animals, including the twenty-foot long medusa jellyfish and the moray eel, are then shown. The film next examines the fishing industry, from giant crab trapping to sponge diving. After a look at Australia's Great Barrier Reef, with its colorful fish and plant life, salmon of the Pacific Northwest are seen fighting their way from the ocean to their upriver spawning ground. Sea mammals such as porpoises, turtles, arctic seals and whales are discussed, as are marine birds. Footage of a whale hunt then is shown. The film concludes with the question "What is the fate of the world?" noting that if the polar caps continue melting at a steady rate, the earth's waters will rise one hundred feet, enough to submerge every coastal city worldwide.