"Underwater exploration." . . . . . . "World's oceans"@en . . "Discusses the inventions and innovations that have extended the scope of ocean exploration in the twentieth century." . "The world's oceans" . "The world's oceans"@en . . "Discusses the inventions and innovations that have extended the scope of ocean exploration in the twentieth century."@en . . . "Juvenile works" . "Juvenile works"@en . . . . . . . . . . "Oceanography." . .