Clotworthy competed in the 3 m springboard at the 1952 and 1956 Olympics and won a bronze and a gold medal, respectively. At the 1952 Helsinki Olympic 3-meter springboard competition, Clotworthy scored a 184.92 taking the bronze, behind Americans Skippy Browning, who took the gold and Miller Anderson, who took the silver. Americans had a history of dominance in the event and had swept it in every Olympics from 1932-52. Clotworthy would improve on his performance in the 1956 games. In the 1956 Melbourne Games in 3-meter springboard, Clotworthy captured the gold medal but had finished second in the qualifying round to Mexican diver Joaquín Capilla, who had previously won a 1956 gold medal in platform diving. Increasing his focus, Clotworthy scored higher in the final round, easily outscoring Capilla who dropped down to a bronze medal. American Don Harper, had the highest scores in the final round, but as he had scored fifth in the qualifying round which counted in the final scoring, he could only move up to the Silver medal. Clotworthy won two medals at the 1955 Pan American Games capturing a silver medal in platform diving and a bronze medal in the 3 meter springboard. He met Cynthia Gill at the '55 Pan Am Games, after she won the 100-meter backstroke bronze medal.
Marriage After meeting at the 1955 Pan Am Games, Clotworthy married Cynthia Gill, on March 22, 1958 at St. Thomas Episcopal Church in Hanover, New Hampshire while Bob was coaching swimming and diving at Dartmouth University. Gill had attended Fort Lauderdale's
Pine Crest School, an exceptional swim program and had competed for the Fort Lauderdale Swimming Association. Shortly after his marriage, Clotworthy was chosen by the International Educational Exchange Service, of the U.S. State Department, to give swimming and diving exhibitions from June–September, 1958, as a good will gesture in Malaya, Japan, Ceylon, Singapore, Thailand, Egypt, and Morocco, and later spend a week at the World’s Fair in Brussels, Belgium. He was accompanied by his wife Cynthia, and the couple referred to the trip as an 107-day around-the-world honeymoon. ==Coaching swimming and diving==