 Later in the same afternoon he and Fenning were in the Leander coxless four with Philip Filleul and Harold Barker which won a silver medal, losing to the Magdalen College, Oxford crew.In 1909, Thomson was a member of the Cambridge crew in the Boat Race, and won his rowing blue.In 1910, he won Silver Goblets at Henley Royal Regatta partnering John Burn to beat Albertus Wielsma and Bernardus Croon.