Idle Hour estate in Long Island, New York, on the banks of the Connetquot River; Marble House at Newport, Rhode Island; and later at Belcourt, the Newport mansion of his stepfather, Oliver Belmont. As an adult, he pursued his interest in yachting, winning six King's Cups and five Astor Cups at regattas between 1922 and 1938. He served as commodore of the New York Yacht Club from 1922 to 1924. In 1925, he built his own luxurious vacation home at Palm Beach, Florida, that he called "El Solano". (John Lennon, formerly of the Beatles, purchased it shortly before his 1980 murder.) Vanderbilt achieved the pinnacle of yacht racing in 1930 by defending the America's Cup in the J-class yacht Enterprise. His victory put him on the cover of the September 15, 1930, issue of Time magazine (see image above). In 1934 Harold faced a dangerous challenger from the United Kingdom, Endeavour, owned by the aviation pioneer and industrialist Thomas Sopwith. Endeavour won the first two races but Vanderbilt's Rainbow then won four races in a row and successfully defended the Cup. In 1937 he won again in Ranger, the last of the J-class yachts to defend the Cup. He was posthumously elected to the America's Cup Hall of Fame in 1993. In the fall of 1935, Harold began a study of the yacht racing rules with three friends: Philip Roosevelt, president of the North American Yacht Racing Union (predecessor to US Sailing); Van Santvoord Merle-Smith, president of the Yacht Racing Association of Long Island Sound; and Henry H. Anderson. "The four men began by attempting to take the right-of-way rules as they were and amending them. After about six weeks of intensive effort, they finally concluded that they were getting exactly nowhere. It was the basic principles, not the details, that were causing the problems. They would have to start from scratch." In 1936, Vanderbilt, with assistance from the other three had developed an alternative set of rules, printed them, and mailed a copy to every yachtsman that he knew personally or by name in both the United States and England. These were virtually ignored, but a second edition in 1938 was improved, as were following versions. Vanderbilt continued to work with the various committees of the North American Yacht Racing Union until finally in 1960 the International Yacht Racing Union (predecessor to the International Sailing Federation or ISAF) adopted