Early Races had been mostly timed by stopwatches mounted to car dashboards, but as the complication was shrunk, they have been extra frequently seen on wrists, specifically in the F1 and endurance racing heyday involving the ’50s and ’70s. Encouraged by British pilot’s watches from the 1970s, Hamilton’s Khaki Aviation https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/