Certina/ESA Chronolympic, valjoux 728, year 1971

Beautiful and rare Ebauches SA (ESA/ETA) regatta prototype.

Ebauches SA is a Swiss company founded in Neuchâtel on December 27, 1926, specializing in the design and production of swiss movements, notably Valjoux and Venus, to name a few, as well as the design of watch prototypes for various watch brands. Ebauches SA becomes ETA SA Fabrique d’Ebauches in 1985.

The watch is powered by a column wheel movement Valjoux 728, which is notable for being the first regatta movement with the minute chronograph counter positioned in the center. It is one of the rarest Valjoux movements, produced in a limited series for only one year, in 1971.

During this period, this particular model was commercialized  by Certina under the name Certina Chronolympic Regatta.

Dial: A vibrant multi-color dial with unique graphic elements, featuring a tachymeter scale and regatta indicator. The layered design includes shades of navy, red, cream, and blue, with contrasting orange and turquoise accents on the hands.
Center Chronominute and seconds, regatta indicator, designed specifically for sailing competitions.
Hour counter at 6 o'clock, tachymeter scale for speed measurement, making it a multi-purpose tool for sports and navigation.

Case: Brushed stainless steel case,  the size excluding the crown is 40x44 mm, providing a nice presence on the wrist.

Operation:

The chronograph of the ESA/Valjoux 728 movement operates through a complex mechanism that allows for precise measurement of elapsed time. Here are the main steps of its operation:

Start and Stop: To begin timing, you press the push-button located at 2 o'clock. This activates the chronograph movement, causing the central seconds hand to rotate. To stop the timing, you press the same push-button again.

Reset: Once you have stopped the chronograph, you can reset the hands by pressing the push-button at 4 o'clock. This returns the central seconds hand and the other counters to their starting position.

Minute Counter: This movement is unique because it features a central minute counter, meaning that the chronograph's minute hand is also at the center of the dial. This allows for easier and quicker reading of the elapsed time.

Column Wheel: The Valjoux 728 uses a column wheel system to control the start, stop, and reset functions of the chronograph. This mechanism is appreciated for its precision and reliability, providing smooth and seamless action.

Display: The chronograph can display times of up to 60 minutes, which is ideal for regattas and other timed events. The small counter located at the bottom of the dial measures elapsed hours up to 12 hours.

This watch is a beautiful example of watchmaking engineering, combining functionality and aesthetics.