You’ve been expecting it and here it is. My watch column of the day will be dedicated to a brand that I often talk about instore: Tudor!

For several years now, Tudor has been surprising the market with increasingly daring innovations, responding with ever greater precision to the expectations of its enthusiasts, thereby proving its attentiveness and demonstrating strategy clearly geared towards customer satisfaction. This is also demonstrated by the new models presented at the beginning of April during the latest edition of Watches and Wonders 2022. By presenting a brand-new model inspired by the history shared with Rolex through its Black Bay Pro, or by interpreting its GMT model in a version that fans will soon call "GMT rootbeer" like the famous GMT Master with the corresponding nickname, Tudor surprises and pleases us all! Let's admit that we are all won over by these historical designs brought up to date and modernised to thrilling effect! Tudor thus clearly claims shared paternity with Rolex as well as demonstrating its commitment to offering amazing watches bearing the Tudor DNA!


The 2022 edition of Watches & Wonders proved a very fine edition for Tudor, although the brand had not waited for this watch show to treat us. At the end of last year and in partnership with the French Navy ,Tudor presented the Pelagos FXD which was an immediate success in terms of both its aesthetics and its impressive technical characteristics!

Tudor Pelagos

In this cocktail of new models and innovations, surprises and horological delights, I’ve decided to back just a few months to when Tudor presented its all-new Black Bay Ceramic bearing the prestigious Master Chronometer title: a precision timekeeping certification that is both technical and complex – but which I will be happy to decipher for you, so don’t worry. Tudor achieved a major coup with this new Black Bay that even won the “Petite Aiguille” Prize in the 2021 Grand Prix d’Horlogerie de Genève. An almost “logical” reward when one takes time to analyse carefully this watch endowed with an array of astonishing characteristics.

In this column, I retrace some of the history of the brand with the shield and rose imagery before focusing on the Black Bay Ceramic model and its Master Chronometer certification delivered by METAS, in order to really understand why this title is so exceptional.

Tudor GPHG

Tudor, little sister or little brother?

Tudor is indeed a watch brand that shares the same founder as Rolex, Hans Wilsdorf, a visionary and business genius in his own time (and even posthumously if you look at the legacy and values that have survived him in both brands). Tudor is said to be Rolex's little sister, or sometimes its little brother, by analogy with the British royal family.

But what is the reality behind the nickname?

It is important to remember is that these two brands were born from the mind of the above-mentioned Hans Wilsdorf. He was deeply attached to work well done as well as precision, and he understood that the water resistance of a watch was one of the keys to the future of watchmaking. Moreover, he also cultivated sincere values of sharing and philanthropy. When Rolex began to develop and meet with great success, notably with the birth of the iconic Oyster case in 1926, Hans Wilsdorf registered the name of a new brand: Tudor. So why create a new brand when the first could be amply sufficient?

The reason was that Hans Wilsdorf wanted to share his vision with as many people as possible. Through Tudor, he wished to offer "the best quality at the best price", whereas Rolex watches may have seemed inaccessible to some at the time (and perhaps even now).

Tudor History

“For some years now, I have been considering the idea of making a watch that our agents could sell at a more modest price than our Rolex watches, and yet one that would attain the standard of dependability for which Rolex is famous. I decided to form a separate company, with the object of making and marketing this new watch. It is called the TUDOR watch company.”

Thus was born the Tudor brand, whose destiny would long consist in following the example of the big brother or sister, sharing exterior elements with Rolex (the case middle, the case back and the crown), yet distinguishing itself through the design of its dials, and above all by movements sourced from external partners, movement blank manufacturers such as Fleurier – which equipped the very first Tudors with its Calibre 390 – and then ETA and so on.

Tudor born to dare

2017: Born To Dare

In this column, I won't go over all the key dates, to avoid giving you a historical listing. My objective here is to immerse you in the world of Tudor, its culture, its very essence. Offering a contemporary perspective on the brand, without forgetting its roots, is ultimately the best way to understand Tudor.

Tudor_Born to dare

The year 2017 saw the introduction of Tudor's 'Born To Dare' campaign. By then it had already been five years since the brand with the shield and the rose imagery had its Black Bay collection (with the Black Bay Red) and revealed its true nature through its “Born to Dare” slogan.

It dares to dare, whereas its big sister must follow other codes – which is also its strength. Daring through audacity and daring through innovation. In 2015, Tudor shook up the watchmaking world by presenting its North Flag model equipped with a brand-new in-house movement whose vocation is to equip more and more Tudor models: Calibre MT5621.

Tudor and its in-house movements

Tudor mov

This brand-new movement was clearly avant-garde, yet few people really realised it then (which is not so far back as we are talking about seven years ago, at a time when I was not yet a watchmaker). Endowed with a 70-hour power reserve earning it the delightful unofficial “week-end proof” popular seal of approval, this movement clearly exceeds market standards.

In terms of accuracy, the movements are all chronometer-worthy, meaning they have secured chronometer certification attesting to the fact that their average variation in rate falls within a range of -4/6 seconds. In actual fact, Tudor goes further and adjust the timing of all its chronometers to a stricter tolerance corresponding to -2/+4 seconds of average daily variation.

Tudor watch

(In its preferred environment... on my plum tree)

What you need to know about the precision of a movement is that its regulating organ is crucial. The latter, also known as the balance-spring, is what we like to more poetically call "the heart of the watch". The heart of this new movement is made of a technical material that is very popular in watchmaking – but not necessarily used in this particular component – since in this instance it is the variable-geometry balance-spring that is made of silicon. When applied to a balance-spring, silicon offers optimal elastic properties, as well as being non-magnetic, i.e. resistant to magnetic fields. Its material properties also make the balance-spring and its ‘breathing in and out’ both extremely homogeneous and stable. The performance observed is unquestionably impressive, as is the stability of the rate enabled by this silicon balance-spring. The North Flag that I wore continuously for two years offered me a daily precision corresponding to +0.5 seconds of average daily variation – which is a tough act to beat! There were even some months when the watch remained at +1 second for the whole month – a score that would thrill even the most experienced precision timer!

Tudor wristshot

A chronicle would not be complete without a wristshot!

The Black Bay collection

Anyone interested in Tudor will be aware of the Black Bay collection. As I mentioned earlier, it was in 2012 that Tudor launched the first Black Bay in a Red version. The watch quickly became an icon with its golden font, its beautiful golden rose logo and of course its red bezel insert.

This Black Bay model, as well as those that were to follow, represented the essence of the brand and in some way the affirmation of its own identity. Was this about staking a claim, or simply deciding to reveal the truth about itself that it had never yet ‘dared’ to express? "Born To Dare" is ultimately the proclamation of what Tudor has always been, as the Black Bay collection has been demonstrating for a decade now.

  Tudor Oyster Prince Submariner – Ref. 7924 "Big Crown", 1958

Tudor Oyster Prince Submariner – Ref. 7924 "Big Crown", 1958

Drawing inspiration from history and heritage, Tudor is committed to a love of classics while rejecting the status quo. The Black Bay collection reflected this driving force, as is most powerfully illustrated in the Black Bay Fifty-Eight which was inspired by the 7924 model from 1958. It is also nicknamed "big crown" because of its oversized winder enabling this watch to be water resistant to 200m. It picks up certain inspirations such as the graduated scale on its bezel insert, the red triangle, the dial hour-markers and its golden font. It also features a big crown, although perhaps less disproportionately large than on the 1958 model. On the other hand, the current model is clearly contemporary and asserts its identity through the Snowflake hands inherited from its 1969 Submariner model and its shield-shaped logo.

Tudor Submariner 9401 "Snowflake" and Tudor Black Bay 58 Blue

Tudor Submariner 9401 "Snowflake" and Tudor Black Bay 58 Blue

Since its release, this Fifty-Eight version has appeared new versions: in steel with a blue dial, followed by a silver-toned variation with a taupe dial and an 18K yellow gold iteration with a green dial. "Born to Dare", Tudor is a brand that dares and this daring is rewarded by the public's rave reception of all these new products.

Ever further: Black Bay Ceramic Master Chronometer

The end of 2021 brought a big surprise with a new addition to the Black Bay collection: the Black Bay Ceramic Master Chronometer. Intriguing at first sight, this watch features a black ceramic case, black bezel, black dial and black strap. The hands and hour-markers strike a powerful contrast and the overall look is one of being dressed to impress!

The movement is the existing Calibre 5602 powering the Black Bay collection, yet one quickly realises there is something very different, as the transparent caseback enables one to admire a reworked and distinctively total-black movement! It is already magnificent to the naked eye, but examination through a magnifying glass reveals something truly extraordinary.

The movement is not only attractive, but also represents a logical continuation of Tudor's work over the years to present ever more technical and innovative timepieces, as this movement is the one driving the very first Tudor to be awarded the prestigious Master Chronometer title. This extremely strict certification involves a list of technical criteria that required Tudor to rework this movement and the materials used in order to meet them. The result is a movement architecture that we know from the 5602, yet totally reworked and adapted to become a Master Chronometer.

Tudor Black Bay

A look at the specifications of the watch confirms that this is an authentic Black Bay endowed with all the corresponding characteristics: water resistance to 200 metres; a 70-hour power reserve; and optimised shock resistance thanks to the traversing bridge of the MT56xx calibres. In short, on paper it embodies the excellent quality we have come to expect from a model we know, love and trust.


Admittedly, a name like "Black Bay Ceramic" is a give-way that one of the watch's singularities lies in the fact that it is made from this high-tech material! We should thus now take a look at the different techniques involved in making a ceramic case. There are in fact basically two: injection moulding and monobloc machining. My chronicle on Hublot outlines the fundamental principles of manufacturing ceramics by injection as applied to watchmaking: from constituting the feedstock (i.e. the powder which is used as a formula for the ceramics) to sintering, as well as injection moulding. This is a rather technical article, but it is necessary to understand the difference with the choice made by Tudor.

That is because Tudor took the second option: machining from a ceramic block. Why did they do this?

Ceramic is a material whose properties are naturally of interest to the watch industry, not only because it is non-magnetic, but also because of its lightness and extreme hardness making its surface virtually scratch-proof.

Choosing to machine from a ceramic block involves relying on extremely delicate and expensive machining. This is costly in terms of production tooling and also in terms of the volume of scrap, so I ask again: why this choice?

Injection moulding can be considered as requiring extremely precise expertise and the greatest difficulty lies in accurately mastering all the steps in the production process. Brands like Chanel who already have this know-how are very rare and in their particular case, one can well imagine that their production capacity is largely devoted to their own collection.

In short, or at least this is how I interpret it, Tudor has made the best choice to ensure a high-quality ceramic case with optimal properties. The trade-off is the cost of production. This is a pleasing answer, because it once again demonstrates the brand's commitment to quality before all else!

While this Black Bay Ceramic is thus endowed with multiple assets, a significant proportion of the interest it arouses lies in the Master Chronometer that we are now going to unpack.

Master Chronometer – METAS: What on earth does it mean?


The Master Chronometer title is a precision timekeeping (chronometer) certification, but not the only one! It is issued by METAS, the Swiss Federal Institute of Metrology – the latter being the study of measurements.

To obtain this precious recognition, a watch must meet the following criteria:

1. The watch must be "Swiss Made" and meet the requirements set out by ordinance of December 23 1971 on the use of the name "Swiss" for watches (RS 232.119), in its latest current version.

In short, when you own a Master Chronometer watch, it is an additional certification of the origin and authenticity of the Swiss Made label of your watch.

swiss made

2. The movement must be certified as a "Chronometer" according to ISO 3159:2009 by an accredited laboratory ISO/IEC 17025:2005.

As I mentioned a little earlier, a chronometer certification such as the one delivered by the COSC attests to the precision of a watch movement. This certification involves a succession of precision checks over several weeks, in different positions and temperature conditions. The current chronometer standard as laid out in the above-mentioned ISO standard is an average daily variation in rate over the entire test period falling within the range of -4/+6 seconds.


This point relating to the movement alone is merely a pre-requisite for a watch to be submitted to the various tests provided for by the METAS. Once this condition is met, the movement is fitted into the watch, and it is the complete watch that will be tested. This aspect is very important, because the chronometric tolerances to earn the title of Master Chronometer go even further than the known tolerances of -4/+6 seconds per day – as we’ll see in the next point.

3. The movement AND the watch must undergo test cycles and meet the technical criteria as defined in the METAS-N001 standard, of which I will provide the reference at the end of this article.

Deciphering this particular clause means reading all 18 pages of the reference cited. I have done so for you, and here is what you need to remember:

  • From a precision standpoint, the watch is checked across several days, at different temperatures and in several positions, much like the COSC test. The difference is that in the case of the Master Chronometer, the requirement is to have an average daily variation in rate of 0/+5 seconds per day. What does that mean in practice? It means that the watch must not be running late after all these tests, which are performed under strict conditions. It must achieve an average daily variation in rate of between 0 and 5 seconds. If we compare with the current chronometer standard which is -4/+6, seconds, the latter means that a movement will have a precision whose tolerance is measured on a scale of 10 seconds. In the case of a Master Chronometer, it is not just the movement but the entire finished watch that will have a precision measured on a scale of 5 seconds! A precision criterion that is simply twice as strict! Not bad...
  • The power reserve of the watch is tested and measured and must at least match the figure communicated by the brand. In the case of the Tudor movement, the 70-hour power reserve corresponds to almost three days of operation without stopping.
  • Another criterion for this certification is a resistance to magnetic fields up to 1.5 Tesla, equivalent to 15,000 Gauss. Just to give you an idea of how extreme that is, the only similar magnetic fields we might be subjected to in our lives are those emitted by an MRI scanner, which can emit up to 13,000 Gauss. And you usually take your watch off when entering this type of machine. The interesting thing about this test is that it is not isolated, as the magnetic field resistance test phases are integrated within the precision test cycles!

champ magnétique

Magnetic field axis    Illustration    Magnetic field      Minimum time                       

6 to 12 o’clock                              1.5                        30

The tolerance for the magnetic field is 0/+0.20 T. The magnetic field must be uniform across the entire volume occupied by the watch.

  • Finally, a technical water-resistance criterion is tested, insofar as the entire watch is checked. In the case of the Black Bay Ceramic, given that it is a watch with a water resistance of 200 m and a unidirectional rotating bezel, it must meet the requirements defined by the ISO 6425:1996 standard for divers’ watches. The watch must in fact resist an overpressure of +25% compared with the announced water-resistance value. Simply put, if a watch is advertised as water-resistant to 200 m and must resist an overpressure of 20 bar, it will be tested at an overpressure of 25 bar. To learn more about the water resistance of watches, I invite you to read the chronicle this topic HERE


As you will have understood, the tests to which the watches claiming the title of Master Chronometer are subjected are extremely strict, and to earn such a title is truly a demonstration of excellence both in terms of chronometric performance and the overall robustness of the watch.

4. The next two criteria deal with organisational issues on the processes of accreditation and regular auditing of the testing methods, etc.

In practice, what the last two criteria involved is that METAS regularly monitors and performs audits on the testing laboratories. A reference framework also defines the fact that all watches are tested and that that the laboratories conferring the Master Chronometer title do not work on the principle of random sampling.

METAS develops and certifies special equipment within the manufacturing facility that will perform the tests. A METAS facility is located within the manufacturing facility and can be accessed exclusively by METAS personnel, so as to ensure the integrity of the certification.

Between 5% and 10% of the certified watches are subjected to random rechecking and retesting in Bern at the METAS premises.

All the criteria governing certification, controls and audits, as well as equipment updates are thus defined by a precise reference framework.


Finally, Tudor has developed a smartphone application, Tudor Watch ID, which enables one to scan the warranty card of a Black Bay Ceramic Master Chronometer watch to access all the details of the watch and the watch's official METAS test results.

In conclusion

In wrapping up this chronicle, which I hope will have given you a dynamic and exciting vision of the Tudor brand, I would obviously like to highlight the new Master Chronometer title of the new Black Bay Ceramic Master Chronometer.

It is undoubtedly an incredible distillation of watchmaking techniques, from its movement to its exterior components, notably thanks to its ceramic case. Everything about this watch has been designed to tick all the boxes of a timepiece that is as accurate as possible, the most resistant to its environment, and endowed with design reflecting the brand’s history while radiating an undeniably modern aura.

Thanks for reading and feel free to share with me your opinion of this watch!