Guy De Clercq was born in 1923 in Groot-Bijgaarden, Belgium. He was a great water skier and highly respected as an ambassador of the sport.
He was World Champion at the 1949 and 1950 water ski jumping championship and tied for first place overall in 1949, the first year the World Championships were held for this sport (at Juan-Le-Pins, France).
He was European Champion in 1949 in jumping and overall, and also won the European jumping championship in 1951.
His brother Claude was European overall champion in 1947, and from 1950 until 1952, with a further eight individual titles.