No. 14: Winter 1981 Supplement
Bit by bit, evidence accumulates showing that Chinese and Japanese ships visited the American Pacific coast long before Europeans. Indian traditions tell of many "houses" seen on Pacific waters. Chinese history, too, tells a charming account of voyages to the land of Fusang. Even old Spanish documents describe oriental ships off the Mexican coast in 1576. Japanese explorers and traders evidently left steel blades in Alaska and their distinctive pottery in Ecuador. Recent underwater explorations off the California coast have yielded stone artifacts that seem to be anchors and line weights (messenger stones?). One line weight found at 2,000 fathoms is covered with enough manganese to suggest great antiquity. The style and type of stone point to Chinese origins for all these artifacts. Apparently, vessels from the Orient were riding the Japanese Current to North American shores long before the Vikings and Columbus reached the continent.
(Pierson, Larry J., and Moriarty, James R,; "Stone Anchors: Asiatic Shipwrecks off the California Coast," Anthropological Journal of Canada, 18:17, 1980.)
Reference. Such putative Asian contacts are covered in our Handbook: Ancient Man. A description of this book is located here.