In 1981, the sixty-three-old Marshall and his wife Pamela moved to Barbados where he would become one of the most important figures in that country's horse racing industry. Among his successes at Garrison Savannah Racetrack, Bill Marshall was a seven-time winner of the island's most prestigious race, the Barbados Gold Cup and a nine-time winner of the Barbados Derby. In 1989 he conditioned Barbados Triple Crown champion, Coo Bird, who would win more races in his career than any other Thoroughbred in Barbados horse racing history. In all, Marshall won twenty-two Barbadian Triple Crown races and earned champion trainer honors eleven times.
