Diving Adventure

About to descend to the sea bottom, they strapped on their gear - face mask, scuba tank, weighted belt, and fins.

Plot
Hal and Roger visit an underwater city off the coast of Australia.

Real Life Adventure
In a note at the beginning of the book, Price writes, "This story is fiction, and Undersea City belongs to the future, not the present. But many incidents in the story are based upon actual adventures in Cousteau's village on the floor of the Red Sea, the U.S. Navy's Sealabs off California, Japan's seaweed and perl farms, oil wells in the Gult of Mexico, sunken cities of Greece and Jamaica, underwater parks of Florida and the West Indies, the submarine town at Monaco and the author's underwater experiences in the Bahamas and South Pacific."