GENEVA.- The wristwatch involved in one of the most compelling episodes in wristwatch making history will appear at auction for the first time in a quarter of a century – its second only sale in a hundred years – at Sotheby’s Important Watches Live Sale due to take place at the Mandarin Oriental Hotel in Geneva on 9 November 2025. The watch will be offered with an estimate in excess of 1 Million CHF / 1.3 Million USD. The Rolex Oyster, the world’s first practical solution to a waterproof wristwatch, was made famous by British endurance swimmer Mercedes Gleitze (1900-1981), when she wore one of the very first models ever created, during her legendary ‘Vindication Swim’ in 1927.

This historically important watch, made unique by its extraordinary provenance, symbolises several major shifts in the history of watchmaking and beyond – including Rolex claiming its newfound status as major global player in watchmaking, leading with ground-breaking innovation; and the birth of modern sports sponsorship as Mercedes Gleitze became Rolex’s first brand ambassador – redefining the purpose of a collaboration between a brand and a celebrity in the process.

The Mercedes Gleitze Rolex Oyster, most likely made in late 1926 before the patent for the winding crown was obtained in early 1927 (the back case includes the mention patent applied for), was made of 9ct yellow gold and is one of a handful of such pre patent Rolex Oyster watches ever to appear on the market. It is also, and by many nautical miles, the most consequential watch in the history of the brand that one could aspire to take stewardship of.

After her legendary swim, Mercedes Gleitze only ever wore her original Oyster watch, despite offers from Rolex to wear other models. Gleitze preferred for Rolex to maintain her “companion” Oyster. The Mercedes Gleitze watch was the star of Rolex’s 50th anniversary celebrations of the Oyster model in 1976, which included an exhibition at the Greenwich Observatory and the announcement of the Rolex Award for Entreprise which has remained a central point of the brand’s heritage ever since. Rolex remained respectful of Gleitze’s enormous contribution to the development of their brand throughout her life and beyond – recalling her achievements and her association with Rolex when communicating the brand’s heritage to this day.

Rolex and Mercedes Gleitze – Two Kindered Spirits Showing the Same Passion for Excellence

The success of both Mercedes Gleitze as the first British woman to swim across the Channel, and the Rolex Oyster as the world’s first practical waterproof wristwatch belies parallel and intertwining stories of extraordinary determination in the face of adversity and challenges: it took Gleitze five years and nine attempts (including her ‘Vindication Swim’) to clinch the British record; and over ten years for Rolex to create a reliable, durable and practical wristwatch that was also waterproof, shockproof and dustproof.

Hans Wilsdorf, the German-born, London-based co-founder with his brother-in-law Alfred Davis of Wilsdorf & Davis in 1905, had been obsessed by the creation of a durable and practical waterproof wristwatch to replace pocket watches since the early 1910s. When they officially registered the trademark Rolex in 1915, the pair focused their effort on wristwatch development and had begun to instruct their case and movement-makers to experiment with hermetically sealed cases, special winding crowns and accurate movements suitable to wear on a wrist. At this stage, “hermetic” watches with screw-down lids and bezels existed but were not for practical daily portable use.

Rolex filed and acquired a series of patents between 1922 and 1925 for new waterproof case and crown systems, but one key missing element was a design which allowed the crown itself to be easily screwed down tightly onto the case, creating a watertight seal. Wilsdorf eventually found and purchased patents from Swiss inventors Paul Perregaux and Georges Peret in 1925 for a screw-down crown system which he improved technically by adding a clutch mechanism paired with a fully sealed case. In 1926, Rolex combined all these innovations into the Rolex Oyster, the first practical waterproof wristwatch with a hermetically sealed case paired with the easy-to-use screw-down crown for which he applied for a patent in October of that year.

When it came to publicising the watch, Wilsdorf seized the opportunity of endorsement by Mercedes Gleitze whom he would have been well aware of due to her record breaking swims and numerous attempts at crossing the English Channel which had been consistently reported in the national press. She was of German descent, like Wilsdorf, although a British citizen by virtue of her birth in Brighton. The common cultural and linguistic heritage would have been instrumental in creating an immediate kinship between the two beyond the recognition in each other of the pioneering spirit that drove them both to success.

The Extraordinary Endurance of Mercedes Gleitze and Victory Over the Channel

Mercedes Gleitze, a smart multi-lingual secretary and typist working in central London, developed a passion for swimming at an early age in Brighton, then in London when she started to get noticed for swimming across increasingly longer stretches of the River Thames. Her first attempt to swim across the Channel was in August 1922 and at that point in time, only men had managed to accomplish this feat (as early as in 1875 by British Captain Matthew Webb over nearly 22 hours).

When a woman – Gertrude Ederle – first successfully crossed the Channel, it was on 6 August 1926, a record-breaking feat achieved over 14h39m – beating all previous times achieved by men. American Olympic swimmer Gertrude Ederle was born in New York of German parents, like Gleitze. Ederle’s astounding achievement would have spurred Gleitze on to now become the first British woman to achieve the feat. Ederle had won by crossing the Channel from France, rather than the traditional start from the English coast, so Gleitze switched strategy and began her next swims (including the Vindication Swim) from Cap Gris-Nez near Calais in France.

Her 7 October 1927 swim was successful – accomplished in 15h15m – but the legitimacy of the achievement, was thrown into doubt three days later when a rival claim was made by open water swimmer Mona McLennan (also known as Dorothy Logan). Although McLennan admitted her claim was a Hoax to the press, on 17 October, Gleitze, had already agreed to defend her title with another crossing on Friday, 21 October. For this swim the conditions had deteriorated and were very unfavourable, leading Gleitze to eventually abandon her swim after 10h24m.

The Vindication Swim and The Dawn of Modern Sports Sponsorship

Logan’s hoax combined with Gleitze’s celebrity status meant that the press would call the Vindication Swim a sporting event of national importance. This led to Wilsdorf contacting Gleitze to ask her to wear the watch which she did around her neck attached by a ribbon. The contract between Gleitze and Rolex was organised and subsequently managed by newly founded S. T. Garland Advertising Service, which went on to merge with Saatchi & Saatchi several decades later, becoming part of one of the world’s most influential advertising agencies. The ‘Vindication Swim’ was an extraordinary affair with boats following Gleitze’s crossing with members of the press. Also present was a small flotilla carrying friends, family as well as musicians to help keep Gleitze alert in the icy and choppy water, all bearing witness to Gleitze’s extraordinary endurance. So important was the event that the Daily Mail chartered an aeroplane to take aerial photographs of the swim, which they published on the front page the following day.

Gleitze was the first athlete whose sporting achievements were used to verify the engineering prowess of a product. The tight interplay between the record-breaking endurance swimmer and the Rolex Oyster submersion was the perfect test of the durability of the watch and became a compelling, utterly believable and empirical proof of the claims made by Rolex.

Rolex officially referred to Gleitze’s role as a testimonee within the Oyster’s promotional campaign they deployed shortly after the ‘Vindication Swim’– thus reinforcing her active role in the thorough testing of their Oyster’s technical abilities. Rolex built an entire campaign (“the watch that defied the Channel”) around her achievement, publishing a full-page advertisement in the Daily Mail (24 November 1927) celebrating the fact that the Rolex Oyster “kept time despite being immersed in water for over ten hours”. Rolex, throughout the nearly 100 years since the Mercedes Gleitze Vindication Swim, has continued to refer to it as a fundamental moment in the brand’s history associating it with “the debut of the Rolex Oyster and its triumphant march worldwide” as well as marking it as a “turning point” for the brand and watchmaking as a whole.