At the age of seven Wouly de Bie got his first swimming certificate before taking up water polo just two years later. De Bie played as a goalkeeper for the rest of his career, becoming one of the best keepers in the world. By 1977 he had been selected to play for the Dutch national team and he competed at the 1980 Moskva and 1984 Los Angeles Olympics. He ended his playing career shortly after the LA Games and took up a job in the military police. This was short-lived, however, with De Bie going back to water polo, this time as a coach in Kuwait. He coached domestic teams in France, the Netherlands, and Venezuela, as well as coaching the national teams of Kuwait, New Zealand, and Canada.