Sherpa Watches

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Sherpa Watches

Sherpa Watches

Sherpa Watches

Martin Klocke, Founder of Sherpa Watches

Martin Klocke is a Swiss born passionate engineer, Buddhist, and long-time admirer of iconic watch brands like Roamer, Certina, Bulova, Enicar, Junghans and Favre-Leuba. He studied the now classic Sherpa watches from the past and is dedicated to have these celebrated models reborn and made available to a world-wide audience. In Switzerland, Martin Klocke unravelled the secrets of original Compressor cases by highly respected watch case producer Ervin Piquerez, to stay true to the original technology, style, and quality. Together with a dedicated team of Swiss and German craftsmen, he is the driving force behind the first Sherpa Watches OPS and Ultradive models: divers that proudly show their heritage and meet the today’s demands in terms of accuracy and durability.

The Sherpa Ultradive and the OPS, wrist favourites of countless professional deep-sea and military divers from the past, cult actors like Alain Delon and now world-famous musicians like Ed Sheeran, sport a robust bayonet compressor case that measures 40 mm in diameter, excluding the crowns and crown protection. Both case size and crown protection guards are identical to the original Sherpa models from 1968, just like the revolutionary water-resistant technology as developed by Ervin Piquerez S.A. (EPSA) – yet updated to today’s technologies. The unique bayonet compressor case back construction, originally named EPSA-STOP, and the re-invented MONOFLEX compressor crowns are present in our Ultradive and OPS to grant you the full authentic ‘Compressor Dive Watch experience’. Finally, after more than 60 years, the true ‘Compressor Dive Watch’ will be reborn. Sherpa Watches

Sherpa Watches has embraced the craftmanship and high-quality engineering from the Swiss pioneers. Sherpa have made every effort possible to elevate the concepts and techniques from the golden age of watch making into the present. The timeless designs of the Ultradive and the OPS did not need much finetuning, as their look and feel are as outspoken today as they were half a century ago. On a technical level, Sherpa watches surpass their predecessors in terms of accuracy, water tightness and durability. And as a world’s first there’s an added a hidden gem of minuscule proportions, for large impact. *(see “Mantramatic” below)

Every timepiece created by Sherpa Watches has a story. Because every watch is hand built and represents the craftmanship of all the German and Swiss watch makers, case manufacturers, dial creators and mechanical engineers involved. Their love for the iconic watches that explored oceans and conquered Mount Everest in the 1950s reflects in every detail. Sherpa combines the revolutionary watch case designs from the past with modern techniques and the highest quality materials to ensure our watches will stand the test of time.



Iconic design meets state of the art engineering.

Imagination meets perfectionism.

Devotion meets emotion.
It’s not only mechanics that makes Sherpa Watches tick.

It’s a heart.

The Sherpa OPS  ($6,400 usd)

With its satin finished dark anthracite watch case, the OPS is the rebirth of a model that was favourited by several Navy Forces in the 1960s. The elegantly domed sapphire box glass with internal anti-reflex coating adds to the sleek appearance on the wrist, which enables the rugged tool watch to be worn on any occasion – from the depths of the sea to matching your laptop. The perfect 40 mm size and 13.5 mm height adapts to all occasions and wrists. While being water resistant up to 20 bar (equivalent to ca. 200 m depth) and equipped with the high-quality Swiss Mantramatic MM01 movement, based on Sellita SW200-1 premium (top) range, this classic design is fully upgraded to today’s standards.

The Sherpa Ultradive  ($6,600 usd) 

The Ultradive has a 40 mm diameter, an eyepopping double-crown protection and a unique ‘double lollipop’ seconds hand, just like the original design from 1964. The curved dial with applique indices featuring diamond cut chamfers, just like on the hands, give the watch a sparkling attitude. The internal diving bezel, operated by the upper crown, features the special dayglow Sherpa Orange Swiss Super-LumiNova Grade X1 that give this watch a unique look – elegant, but a tool watch at the same time. Like its sister model the OPS, it is 20 bar (equivalent to ca. 200 m) water resistant and features the unique compressor mechanism in the case back and (no screw down) crowns.

SHERPA “Mantramatic”

The mechanical movement inside the Ultradive and OPS is not a regular automatic. It is a Mantramatic! Sherpa has microscopically laser engraved a traditional Tibetan Buddhist mantra OM MANI PEME HUNG, which is very commonly used in the Sherpa region on two of the wheels, (using a custom created Tibetan font). Following widespread Himalaya Buddhist tradition used in prayer-wheels, the wheels in the movement rotate constantly, sending out vibes of love, wisdom and compassion from your wrist straight into the world – 30 million times per year. With the naked eye you will not notice the mantra is there. Instead, you will feel it.

The Rebirth of a true Super Compressor! SO, What’s a Compressor? 

A water-resistant watch with two crowns is a (super) compressor watch, right? Not quite. In a way, this could be true for vintage watches, but in fact, not always. And for today, this is even more doubtful, as nearly all double crown & internal bezel watches just use traditional sealing technology and only look like the watches from the past. The Ultradive and OPS watches are equipped with two crowns. And then some, because the true (super) compressor or bayonet compressor technology goes deeper than the naked eye can see. So, let’s dive in!Sherpa Watches

The technology behind the super compressor was introduced in the 1950s. At that time, it was not easy to design and build a water-resistant watch, especially for mass production. The sealing materials were not yet as reliable as today, and some materials we use nowadays were not even invented or developed to sufficient quality standards.

So, watch brands had to be very inventive to achieve water-resistance. A company that was ahead of its time, was Ervin Piquerez SA, also known as the abbreviation EPSA to watch connoisseurs. The designers and engineers of the company, which was at some point in time the largest manufacturer of watch cases in the world and worked for all the big watch brands, had several groundbreaking ideas during the 1950s and addressed the problem of achieving water tightness in many clever ways.

The (Super) Compressor technology

Up till the early 1950s, sealing materials were usually not of the quality and characteristics that were needed to withstand rising water pressure. In many cases, the materials would deform and make the sealing pressure fade over time, resulting in leakages. The technicians from EPSA had a brilliant idea how to solve this problem: they invented a case back technology, called ‘compressor’, which would put the sealing under slight pressure in everyday use, resulting in water resistance under normal circumstances and during snorkeling / shallow diving. When diving lower, the rising water pressure further compressed the case back into the case, resulting in a tighter fit.This avoided high pressure on the sealing over longer periods of time and meant that the sealing materials would last much longer.To come up with an idea like that – to use the force that you want to keep out of the watch to increase the sealing pressure and to make the watch more watertight – is the kind of engineering genuineness that still fascinates today. It has a certain Aikido philosophy to it: use the opponent’s force or attack against himself. Based on this basic engineering principle, EPSA developed several versions of this design.Sherpa Watches The ‘compressor’ system was a snap-fit case back which could compress and thus increase water tightness. The ‘EPSA-STOP’ or ‘bayonet compressor’ (operating crowns) system was a further development of this, and the case back did not snap-fit but was secured by a sophisticated bayonet system, which would also allow the case back to compress under water pressure.And finally, the most famous and probably most complicated of these systems, the ‘super compressor’, which combined a screw-in case back design with the compressor feature – also allowing compression of the case back to happen.EPSA also invented a special crown system, called ‘MONOFLEX’, which was also using compressor technology. And finally, EPSA was responsible for developing the internal turning bezel: The complete concept EPSA had created in the middle of the 1950s was ‘GRAND FONDS’, and it included all technologies mentioned here: compressor case back, compressor crowns, internal turning bezel and specially designed plexiglass crystals, usually with metal ring reinforcements. However, this name was never recognized by the consumer market. GRAND FONDS was usually named ‘super compressor’, at least during the last few years. Yes, it’s confusing.

So, The Sherpa Super Compressor?

As Sherpa are bringing back the most legendary models of the old Sherpa series of watches from the 1960s, it’s important to update the ‘EPSA-STOP’ or ‘bayonet compressor’ system. It is improved by using modern sealing materials and higher precision manufacturing, as well as a new design. This allows to only introduce the case back in one orientation and guarantees a perfectly aligned EPSA logo (the iconic diver helmet!) on the case back.  This new design tightens the case back to the sealing in a way that everyday actions can be performed easily and safely, while tightening the sealing further when exposing the watch to higher pressure from outside. In other words: the Ultradive and OPS will go as far (or deep) as you dare to go, without succumbing under pressure.

The MONOFLEX Crown, a labor of love and devotion!


EPSA called them MONOFLEX crowns and they were an integral part of the whole concept:

  • „Grands fonds“ inner turning bezel featuring a second crown for (dive) bezel manipulation (Brevet 350250)
  • (Super) compressor or EPSA-STOP bayonet compressor case back sealing mechanism
  • MONOFLEX crown (brevet 337462)

When analysing the watches before starting the development, it was apparent that the crowns of the old watches never were screw down, yet 200m (20 bars) water tight. This seemed odd, and Sherpa researched to find out how this actually worked in detail. As EPSA went out of business in the 1980s, and until today nothing remained, it was difficult to find out more about this. But sometimes luck is needed, so a book was found, about EPSA written in French which challenged our school French quite a bit, and it gave hints for further steps for our research. Eventually the Sherpa team discovered Swiss archives where some documents could be found outlining details about the crowns. The old EPSA patent itself (Brevet 337462) was not sufficient enough – as could be expected. Patents should protect, but not educate too much! But then fortune struck… Sherpa Watches

Finally, when researching in an archive the team found a drawing of the crown and incredibly enough, also found the internship report of EPSA’s technical head’s daughter, Mrs. Rondez. This young woman spent some time inside of EPSA and had to write a detailed report about it. Many of us know how tedious it was to write these kind of reports, and now the team were on the receiving end. The team at Sherpa can only thank her to have put down her experience! It taught Sherpa everything they needed to know.

So, these crowns use a tubular shaped sealing which slides over the tube which comes out of the watch. In normal use, this offers enough water tightness. When the pressure is rising, the tubular structure is pressed with higher force around the tube, resulting in a better sealing performance. The process to manufacture this component was injection moulding.

With that knowledge Sherpa went on to redesign the old crown construction. On the old drawing the team found the original crown’s producer and were more than happy to see that they were still in business today as a crown maker. Several phone calls and one meeting later, though, the team had to find out that all the knowledge was lost and that there was no willingness to reinvent this crown design. Yet, Martin is again thankful that they were willing to share the old drawings with him, enabling Martin to have an easier start with the redesign!

Master watchmaker / watch construction specialist, Cyrano Devanthey of Bumont GmbH, made motivation to go forward in redesigning the crown to set up a unique production. So the team updated the materials, changed the design to a more modern production setup and started ordering prototype parts. In Summer 2021 these prototype crowns were tested with the complete watch in air pressure and water pressure. Sherpa can now safely say that they withstand 20 bars (which can be equivalent to roughly 200m depth in diving).

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