Harold Brooke took up sailing at the age of nine and made it a lifelong pursuit. Despite having the use of only his left arm, he found notable success in the sport, with his greatest moment coming when he was selected to represent Australia in the Dragon class at the 1960 Rome Olympics. There, alongside Alan Cain and John Coon, he placed 11th in a field of 27 competitors. He and Cain, with the non-Olympian Jack Fitzgerald, attempted to qualify for the Dragon class tournament at the 1964 Tokyo Games, but were not successful. By career, Brooke was in the typewriter business and his son Noel was also a competitive sailor who ran a sailmaking business.