A marine Chronometer on the wrist, the Rolex Oyster

WORLD FIRST The first ever “Class A” certificate granted by the Kew Observatory to a wristwatch was awarded to a Rolex, after extensive tests of its chronometric precision

Just over 100 years ago, in 1914, the Kew Observatory in Great Britain granted a “Class A” chronometer certificate to a wristwatch for the very first time – a watch made by Rolex. Until then, such a certification, which attested to the highest chronometric precision, had generally been awarded only to large marine chronometers after extremely rigorous tests. Rolex was the first to prove that a wristwatch could be just as accurate as the clock-like marine navigation instrument – something that was scarcely believable at the time. This milestone marked the advent of the modern precision wristwatch and Rolex went on to become the largest manufacturer of chronometer-certified watches.

PRECISION An example of a late 18th century marine chronometer, made by French watchmaker Louis Berthoud.

An example of a late 18th century marine chronometer, made by French watchmaker Louis Berthoud.

HIGHEST STANDARD OF PRECISION This first “Class A” chronometer wristwatch was a feat of miniaturized precision that met the most stringent criteria in the world. Kew certified the accuracy of marine chron om eters, which was vital to determine a vessel’s position (longitude) on the high sea. After 45 days of tests, in five different positions and at three differ ent temperatures,
the Rolex wristwatch matched and even exceeded the standards expected of the finest marine clocks. These onboard instruments could not
deviate by more than a few seconds per day without putting the safety of the ships at risk. The Rolex wristwatch chronometer certified by Kew on 15 July 1914 recorded an average daily variation rate of only +1 second. In those early years of the 20th century, pocket watches were the timepiece of choice, due to their robustness and relative accur acy. A reliable, high-precision wristwatch was the stuff of utopian dreams. Yet, from the beginning, Rolex founder Hans Wilsdorf was convinced that the small timepiece represented the future of the watchmaking industry and could be adapted to the ever more active and sporting lifestyles emerging at the time. By obtaining a top-class Kew certificate, Rolex demonstrated that precision in a small format was not only conceivable but also achievable, and could rival the best timepieces of the era. It marked official recognition of the highest worldclass quality for Rolex.

WRIST CHRONOMETER A Rolex wristwatch comparable to the one certified as a “Class A” chronometer by the Kew Observatory.

A Rolex wristwatch comparable to the one certified as a “Class A” chronometer by the Kew Observatory.

THE IDEAL WATCH FOR YACHTING The ideal watch for yachting Rolex’s next objective was to design a perfectly waterproof case to protect the movement and maintain its certified precision. This was accomplished in 1926 with the invention of the Oyster, the world’s first water proof wristwatch, thanks to an ingenious patented case system featuring a screw-down bezel, case back and winding crown. The name, Oyster, was inspired by its capacity to remain indefinitely submerged in water without risk of damage. It was not only waterproof, but also dustproof, for dust and sand are formidable enemies of watch mechanisms. The brand perfected the concept of the modern watch in 1931, by developing and patenting the self-winding Perpetual rotor system, which is driven by wrist movements. There was no longer a need to wind the watch manually with the winding crown, a critical point for maintaining waterproofness. This self-winding system, also patented, ensured a constant power reserve. As a result, the Rolex Oyster Perpetual accumulated three fundamental qualities: it was precise, water- proof and self-winding, making it ideal for use on the high seas. Following improvements in certification and accuracy standards over the decades, the brand’s leadership in chronometric precision continues today. All Rolex Oyster models are officially certified chronometers and new-generation movements provide a superlative level of performance which is twice as demanding as the official standard. They bear the heritage of the pioneering role played by Rolex in bringing precision to the wristwatch, with the help of the exacting demands that the nautical world placed on the marine chronometer.