He was a six-time national champion who competed at world championships and in the men's eight event at the 1972 Summer Olympics.
[2] He first made state selection for New South Wales in the men's eight which contested and won the 1968 King's Cup at the annual Interstate Regatta.
[9] Six members of the New South Wales winning King's Cup eight of 1968 were selected into the Australian eight to contest the 1968 Mexico City Olympics but excluding Clark and John Nickson.
However Clark and Nickson were named as reserves close to departure, travelled to Mexico and rowed as a pair in a lead-up race.
[2] The entire New South Wales winning King's Cup eight of 1972 was picked as the Australian eight to compete at the 1972 Munich Olympics.