Early Races had been generally timed by stopwatches mounted to vehicle dashboards, but because the complication was shrunk, they had been additional generally found on wrists, especially in the F1 and endurance racing heyday involving the ’50s and ’70s. Inspired by British pilot’s watches through the 1970s, Hamilton’s Khaki Aviation https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/