Regatta version of cal. 9100.
The P.9100/R calibre is a development of the P.9100 automatic calibre with chronograph function. With its flyback chronograph with vertical clutch and column wheel, the P.9100/R is identical in architecture and diameter (13¾ lignes) to the P.9100 but it is a little thicker (9.55mm) and it has 26 more parts (328 altogether) as a result of the greater constructional complexity resulting from the addition of the Regatta countdown function. The indication of the countdown to the start is displayed by the two central hands, and it is controlled by the push-button at four o’clock. The minute hand moves backwards by one minute each time the push-button is pressed, until it reaches the position required for the duration of the countdown. At this point it is only necessary to press on the push-button at ten o’clock to start the chronograph function. The hands begin to move, indicating the minutes and seconds which remain before the start, and when the countdown is completed, they continue to measure the time, thus displaying the time elapsed since the start of the race until the chronograph is stopped. The device which enables the minute hand to be moved backwards when the countdown function is operated is controlled, like the whole chronograph, by the column wheel. This is taller than the one in the P.9100 calibre so that it can engage the correcting lever which is mounted higher up, being located on an additional plate.