In 1963, Rolex launched its iconic chronograph, the Daytona, named after the famous Daytona Beach racing circuit in Florida. Replacing the reference 6238, the reference 6239 is the first to bear this name and to have the "Cosmograph" dials. Fitted with a smooth steel bezel with tachymeter scale which adds a sports look to the watch, it is equipped with a manual movement Valjoux 72B or 722 modified by Rolex which is extremely reliable. Produced until 1969, the ref. 6239 embodies a turning point in the history of the manufacture, which wishes to meet the expectations of the modern man by creating a sporty and classic, reliable and robust watch.