rolex yacht master superlative chronometer officially certified

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What is the Rolex Superlative Chronometer Standard and why does it matter?

Editor’s note: Timekeeping standards are suddenly cool again. Omega has been steadily touting the benefits of their Master Chronometer certification, Patek has their own standards, and Rolex recently upped their game with the Superlative Chronometer Standard. But what is it? This article from a while back explains everything you need to know.

Since 1951, nearly every watch leaving Rolex’s Geneva facility has been a certified Chronometer, and from 1957 onwards, Rolex has been using the term “superlative” on their dials to describe that their watches don’t just meet chronometer standards, but exceed them. Design purists might bemoan the resulting text-heavy dials that declare an Oyster to be “superlative chronometer officially certified”, but Rolex’s nigh-unimpeachable reputation for quality and accuracy has a lot invested in these words. In fact, in late 2015, the brand quietly updated their Superlative Chronometer Standards to make them even more stringent.

If you were lucky enough to get your hands on a steel Daytona or a recent Datejust 41, Rolex guarantees your watch is accurate to -2/+2 seconds per day, after casing, compared to the -4/+6 per day for the uncased movement that COSC requires, or the 0/+5 in Omega’s Master Certification. Rolex’s continued commitment to testing and accuracy doesn’t just show they recognise the importance of reliability, but that they deem it vital to be more accurate than the competition.

Rolex determines this accuracy through a series of external and internal tests. Completed movements are still sent off for official COSC certification. After this, the movement is cased and then tested using (according to brand literature) “unparalleled testing methodologies and new high-technology equipment to certify each of its watches (…) according to its own criteria which exceed watchmaking norms and standards”. These tests guarantee the performance of the watch with relation to precision, power reserve, waterproofness and self-winding, using methods that simulate real world wear and conditions. On top of that, the warranty accompanying this standard (represented by the green seal that comes with your watch) has been bumped up to five years.

What does this mean to those of us who buy and wear Rolex? Well, it means that the people who made your watch spent a lot of time and money ensuring it would provide you with class-leading accuracy and reliability now and in the future. To commit to this level of quality across Rolex’s high production is, frankly, an incredible technical achievement because it leaves so little (four seconds, to be precise) margin for error.

However, if you were inclined to be critical, you might have noticed that aside from the COSC testing, all the other testing and tweaking is internal, and not validated by an external authority, unlike Omega’s METAS-certified testing, nor does Rolex make the individual results of each watch publicly available. Rolex has never been particularly renowned for their transparency, so the fact it’s opted to keep its methods private isn’t that surprising, but given the brand’s track record and the difficulty in obtaining one, I don’t think it’s a cause for concern for most.

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Master Chronometer vs Superlative Chronometer

Accuracy has always been an important point of pride and marketing for luxury watch brands. For over a century, the term “chronometer” has been used to denote timepieces that meet a high standard of precision. Chronometer certification began in Switzerland in the early 1900s to assure consumers that a watch could keep accurate time. 

Traditionally, chronometer designation was granted by the COSC, or Contrôle Officiel Suisse des Chronomètres. This independent agency puts uncased watch movements through a series of tests over multiple days to measure their timekeeping accuracy under different positions and temperatures. If a movement successfully passes these tests within set tolerance levels, it is certified as a chronometer. 

However, some watch brands have recently developed their own even more rigorous certification processes to indicate a new level of timekeeping excellence. The popular watch brand Omega debuted its “METAS” certification in 2015 to signify watches that exceeded COSC standards. Not to be outdone, Rolex introduced its “Superlative Chronometer” certification the following year.

Both the Master Chronometer and Superlative Chronometer labels indicate meticulous in-house testing of fully assembled watches, not just bare movements. They represent a new era of accuracy standards for luxury timepieces. In this article, we will compare these two precision certifications and the state-of-the-art facilities and procedures used to obtain them for luxury watch collections and brands .

Contrôle Officiel Suisse des Chronomètres (COSC)

To understand Master Chronometer and Superlative Chronometer designations, it helps first to explain the baseline COSC certification process. COSC, or the Official Swiss Chronometer Testing Institute , was established in 1973 to standardize chronometer certification on behalf of the Swiss watch industry. 

Brands send their uncased movements to COSC facilities to undergo precision testing. The movements are individually tested over 5 different positions and 3 different temperatures for a period of 15 days. The results are measured against COSC requirements for an average daily precision between -4 to +6 seconds per day. Movements that successfully maintain accuracy within this range across all the tests are officially certified as chronometers. 

This independent verification by COSC is widely respected and considered an achievement of watchmaking excellence. However, some brands strive for even better performance than the baseline COSC standards. Omega and Rolex have developed their own in-house facilities and certification processes to assure consumers of master-level chronometric precision in real-world conditions. 

Omega’s Master Chronometer Certification

In 2015, Omega unveiled its new Meteorite-Crater proven technology and facilities for Master Chronometer certification. This process tests fully assembled watches, not just bare movements like COSC. Omega simulates real-world conditions to verify performance and durability. 

The Master Chronometer testing protocol has 8 separate tests. It starts with COSC-certified movements, then further evaluates the cased watch. Some tests focus on accuracy, like timing precision, power reserve, and deviation. Others test resilience, like exposure to 15,000 gauss magnetic fields and temperatures between 0 to 50 degrees Celsius. 

If a watch passes all Master Chronometer tests within specified tolerance levels, it is certified to perform with precision, magnetic resistance, and reliability. Omega has developed special alloys and movements like the Co-Axial calibers to meet these Master Chronometer standards. This certification verifies chronometric excellence for the entire watch, not just its movement. 

Rolex’s In-House Testing

Not to be outdone, the Swiss-made watch brand Rolex introduced its own in-house certification called the Superlative Chronometer. While similar in name, the Superlative Chronometer process has some key differences from Omega’s Master Chronometer. 

Rolex built new state-of-the-art facilities next to its headquarters in Switzerland for its proprietary testing. The Superlative Chronometer certification puts assembled Rolex watches through a battery of tests that simulate conditions watches encounter in real-world use. 

Testing includes exposures to temperatures between -10 and +50 degrees Celsius, humidity levels of 95%, and magnetic fields up to 10,000 gauss. The watches are tested at different stages of assembly for precision, waterproofness, self-winding capabilities, power reserve and other functions. Strict performance criteria must be met across all areas for Superlative Chronometer certification. 

This in-house verification provides assurance to Rolex owners that their watch has been rigorously tested beyond generic chronometer standards. Rolex takes pride in its self-sufficiency and vertically integrated manufacturing capabilities that allow for this level of quality control. 

Key Differences

While the Master Chronometer and Superlative Chronometer labels have similarities, there are some important distinctions between Omega and Rolex’s proprietary precision certifications: 

• Testing state: Master Chronometer tests fully assembled watches. Superlative Chronometer tests watches at different states of assembly. 
• Magnetic resistance: Master Chronometer tests up to 15,000 gauss resistance. Superlative Chronometer tests up to 10,000 gauss. 
• Temperature range: Master Chronometer tests between 0 to 50 degrees C. Superlative Chronometer between -10 to +50 degrees C. 
• Timing precision: Master Chronometer requires -0 to +5 seconds/day average. Superlative Chronometer is -2 to +2 seconds/day. 
• Power reserve testing: This is tested under Master Chronometer but not specified for Superlative Chronometer. 
• Waterproofness: Superlative Chronometer includes waterproofness testing, which Master Chronometer does not. 

While both are highly demanding certifications, Rolex generally sets tighter precision tolerances. Omega focuses more on magnetic resilience and real-world conditions. But both represent impressive technical achievements in chronometric performance. 

Other Watch Brands That Have In-House Certifications

Omega and Rolex are not the only brands with proprietary chronometer designations. Other watchmakers have also developed in-house certifications to verify standards beyond generic COSC testing.

Tudor, Rolex’s sister brand , introduced its “MT5612 Chronometer” certification in 2015 for its in-house movements. Like Rolex’s process, it tests the cased watch in multiple positions with a tolerance of -2 to +4 seconds/day. Breitling uses the name “Chronometer” for its in-house testing, which focuses on precision, robustness, and water resistance. Cased watches must pass a 5-step process not too dissimilar from Omega’s Master Chronometer.

TAG Heuer has its “Master Chronometer Calibre Heuer 02” certified in-house before encasement. They are then further tested after casing for accuracy, waterproofness and automatic winding.  

The Panerai luxury watch brand has developed sophisticated equipment at its Neuchatel manufacture for in-house testing beyond COSC standards. Watch certification takes place periodically, even after the sale.

Patek Philippe is known for their meticulous quality control and precision in watchmaking. Since 2009, the company has implemented the Patek Philippe Seal, their own independent certification that ensures only the highest quality watches leave their workshops. To receive the Patek Philippe Seal, each watch must pass over 500 separate quality tests, going well beyond the standards of the prestigious Geneva Seal. 

While not as widely marketed as Omega and Rolex’s labels, these other in-house certifications show that striving for utmost chronometric precision has become an industry-wide priority. Technologies and testing capabilities continue to rapidly evolve. 

The Master Chronometer and Superlative Chronometer designations represent a leap forward for chronometric excellence in the watch industry. While the trusted COSC certification will likely remain the baseline standard, Omega and Rolex have paved the way for more rigorous in-house testing. 

Both brands have invested heavily in state-of-the-art facilities to simulate and verify real-world performance. This allows them to hold assembled watches to a higher chronometric standard than generic COSC-tested movements. Though there are slight differences in testing parameters, Master Chronometer and Superlative Chronometer certifications prove these watches have passed intense examinations well beyond the norm. 

Of course, for most buyers, such nuanced precision is somewhat academic. But this technical quest for perfection is part of the magic of high watchmaking. As materials and technologies continue advancing, these types of proprietary certifications will likely only grow more advanced. Omega and Rolex’s friendly rivalry spurs the whole industry towards ever-higher levels of timekeeping accuracy and customer assurance. 

About Bob's Watches

With over two decades of experience in the industry, Bob's Watches has cultivated a deep passion and expertise in luxury timepieces, making them a trusted authority in the watch community. With a passion for horology and over two decades of experience, Bob's Watches has established itself as a go-to resource for buying, selling, and trading luxury watches. They offer an extensive selection of pre-owned timepieces from renowned brands such as Rolex, OMEGA, Patek Philippe, Panerai, and more. At Bob's Watches, authenticity and quality are of utmost importance. Each watch listed on their platform undergoes a meticulous inspection and authentication process by expert professionals, ensuring that customers can purchase with confidence, knowing they are acquiring genuine and top-notch timepieces. With a focus on exceptional customer service, Bob's Watches strives to provide a seamless and secure buying experience. Their user-friendly website allows customers to explore their diverse inventory, complete with detailed descriptions and high-resolution images. They also offer free overnight shipping and hassle-free returns to enhance customer convenience. Bob's Watches is not only a marketplace but also a valuable resource for watch enthusiasts. Their blog features insightful articles, industry news, buying guides, and educational content to help customers make informed decisions. With a strong BBB A+ rating and recognition from reputable news publications, Bob's Watches continues to be a trusted name in the luxury watch industry. Whether you're a seasoned collector or a novice, rely on Bob's Watches to navigate the world of luxury timepieces with confidence and expertise.

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.css-1c7en8u{font-size:clamp(1.375rem, 1.25rem + 0.3125vw, 3.125rem);line-height:1.1;margin-bottom:1rem;} Oyster Perpetual 36 .css-1g7r01k{font-weight:300;font-size:clamp(0.875rem, 0.9375rem + 0.1563vw, 1.25rem);line-height:1.2;text-wrap:balance;}.css-1g7r01k span{display:block;} Oyster, 36 mm, Oystersteel Reference 126000

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Make the world your Oyster

The Oyster Perpetual 36 with a bright blue dial and an Oyster bracelet.

Bright blue dial, a watchmaking technique.

The sunray finish creates delicate light reflections on many dials in the Oyster Perpetual collection. It is obtained using masterful brushing techniques that create grooves running outwards from the centre of the dial.

Light is diffused consistently along each engraving, creating a characteristic subtle glow that moves depending on the position of the wrist. Once the sunray finish has been completed, the dial colour is applied using Physical Vapour Deposition or electroplating. A light coat of varnish gives the dial its final look.

Oystersteel

Highly resistant to corrosion

Rolex uses Oystersteel for its steel watch cases. Specially developed by the brand, Oystersteel belongs to the 904L steel family, alloys most commonly used in high-technology and in the aerospace and chemical industries, where maximum resistance to corrosion is essential.

Oystersteel is extremely resistant, offers an exceptional finish once polished and maintains its beauty even in the harshest environments.

The Oyster bracelet

Alchemy of form and function.

The Oyster bracelet is a perfect alchemy of form and function, aesthetics and technology.

First introduced in the late 1930s, this particularly robust and comfortable metal bracelet with its broad, flat three-piece links remains the most universal bracelet in the Oyster collection. For the Oyster Perpetual models the Oyster bracelet is fitted with an Oysterclasp.

More Oyster Perpetual technical details

Reference   126000

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Oyster, 36 mm, Oystersteel

Oyster architecture

Monobloc middle case, screw-down case back and winding crown

Winding crown

Screw-down, Twinlock double waterproofness system

Scratch-resistant sapphire

Water resistance

Waterproof to 100 metres / 330 feet

Perpetual, mechanical, self-winding

3230, Manufacture Rolex

-2/+2 sec/day, after casing

Paramagnetic blue Parachrom hairspring. High-performance Paraflex shock absorbers

Bidirectional self-winding via Perpetual rotor

Power reserve

Approximately 70 hours

Oyster, three-piece solid links

Folding Oysterclasp with Easylink 5 mm comfort extension link

Bright blue

Highly legible Chromalight display with long-lasting blue luminescence

Certification

Superlative Chronometer (COSC + Rolex certification after casing)

Learn how to set the time and other functions of your Rolex watch by consulting our user guides.

Oyster Perpetual 36

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