Graduating from Cal in 1934, Duncan Gregg had a chance to row on championship boats at the Intercollegiate Rowing Association (IRA) championships in both 1932 and 1934, as well as the gold medal winning eight at the Los Angeles Olympics. In 1932, he held the sixth seat for the Cal Eight. Gregg was the tallest rower for Cal at 193 centimetres. Gregg studied civil engineering and was a manager for a manufacturer of aluminum products. Two of his sons and a granddaughter also rowed for Berkeley and were national caliber rowers.