Darien Boswell rowed for New Zealand in the eight at the 1962 British Empire and Commonwealth Games, winning a silver medal. In 1963 he competed at the Henley Royal Regatta, winning the inaugural Prince Phillip Challenge Cup for the coxed fours (since discontinued). He was in the four at the 1964 Tokyo Olympics as the New Zealand boat struggled, finishing eighth. Boswell won four consecutive national titles with the Auckland Rowing Club four from 1963-66. He also represented New Zealand at the 1965 and 1966 World Championships. After retiring from competition Boswell managed the New Zealand junior and senior crews, and served with the Organising Committee for the 1978 World Championships at Karapiro.