Chuck Hardy was an American diver on a yawl called the "Research" off the isalnd of Tahuata in the South Pacfic. He was working with a woman named Jerry Peterson, on the ocean floor when the volcano on Tahuata erupted. Jerry and Chuck fell through a fissure into the strange subterranean world of Aquatania. The two of them made many friends and enemies in this land, as they quested for a way to get back home. In Aquatania, Chuck had unusual strength and leaping ability. He was a resourceful fighter and usually carried a knife and a rifle.