Sulley was born in the Guisborough district of Yorkshire. He was educated at Cambridge University and coxed the winning Cambridge crew in the 1928 University Boat Race. In preparation for the Boat Race, he had joined Thames Rowing Club and had come down to the club on Sundays to increase his knowledge of the Championship Course. He was then asked by Jack Beresford to cox the Thames Rowing Club eight in the Grand Challenge Cup at Henley Royal Regatta in 1928. After winning the Grand, the crew was selected to represent Great Britain at the 1928 Amsterdam Olympics. The crew won the silver medal in the eight event.