Kaiyo, a 16,748-ton escort aircraft carrier, was built at Nagasaki, Japan, as a civilian passenger liner. Completed in 1939, she was taken over for use as a transport in 1941, serving under her original name, Argentina Maru. . In December 1942, she began conversion to an aircraft carrier, and was renamed Kaiyo. Conversion was completed in November 1943, and the ship served during the rest of the Pacific War as an escort carrier, aircraft transport and training carrier. She was seriously damaged by British Royal Navy planes in Beppu Bay, Kyushu, on 24 July 1945. Kaiyo was stricken from the Japanese naval register in November 1945 and was scrapped at Beppu Bay in 1946-48.