High Quality Content by WIKIPEDIA articles! A chronograph is a timepiece or watch with both timekeeping and stopwatch functions as well as other functions. Pocket watch chronographs were produced as early as the 18th century but did not become popular until the 1820s. The term "chronograph" is often confused with the term "chronometer," which usually designates a watch that has received a precision certification from the COSC. The Marine chronometer was an accurate timepiece used to enable celestial navigation.