Among the many outstanding choices in the Sinn catalogue I’ve always considered the EZM 13 to be one of the more intriguing options. The thing is, I’ve always been fascinated by diving watches with chronographs that you can actually use underwater. You know how it is with most chronograph watches – everyone will warn you not to engage the chronograph underwater as doing so might compromise the seals of the watch.

I see diving watches with chronographs and I wonder why they exist, especially those that have screw down pushers to prevent accidental engagement of the system. Usable chronograph pushers underwater then are a logical step to enable full functionality of your watch – after all, you paid for the complication didn’t you?

Why the need for a chronograph underwater if you already have a bezel timing your total dive duration? Well, it’s not possible to time a separate event when your dive is already in progress if you only have the bezel. With a separate chronograph on board, you are free to time other events that might crop up, such as decompression stops or a spontaneous deviation from your plan to explore an unexpected cave that you come across.

It’s not a popular feature though, as there are not many chronograph watches that are able to do this. Those that do are typically billed as serious diving options and they are few and far between indeed.

Now discontinued, but having this ability include the noteworthy TAG Heuer Aquagraph that I reviewed in a previous article and Sinn’s U1000 and EZM 13.

Currently available to buy now, some options you have include the Blancpain Fifty Fathoms Chronograph, the Omega Seamaster Professional Chronograph, the IWC Aquatimer Chronograph (to 120m), and now the new Sinn EZM 13.1, which is basically a minor update to the previously mentioned EZM 13.

The power of a cleaner dial - or doing away with the Arabic numerals

So what is the main difference between the Sinn EZM 13 that was discontinued to howls of derision among Sinn fans, and the new EZM 13.1 that was introduced this year in 2022? Well, in three words - “no Arabic numerals”.

Now this is a minor change, and most onlookers would scratch their heads and wonder why Sinn chose to do this. Well, watch lovers, especially those who are fans of Sinn, are nothing if not vocal about the littlest details.

The main point of contention about the EZM 13 was that the Arabic numerals made the dial too cluttered, a criticism also made of its non-chronograph sibling with the same Arabic numerals on its dial - the 500 meter capable EZM 3.

When a “flieger” version of the EZM 3 came out, christened the EZM 3F, what was essentially the same watch, had now pivoted in function to become a pilot’s watch, and so was slightly thinner, came with a bidirectional countdown instead of diver’s bezel and had “only” 200m water resistance. Yet no one fixated on these features. Instead this watch was universally praised for its cleaner dial, now sans Arabic numerals, just as many Sinn fans had hoped for.

The possibility was real then, Sinn would listen to feedback, and very soon, a vocal bunch of fans started imploring the company to release an EZM 13 with a cleaned up dial.

Well it seems, Sinn listened, and what we have in this, to outsiders and non fans of the brand, lukewarm refresh of an older model, is precisely what hardcore Sinn fans have always wanted, the new Sinn EZM 13.1

Now personally, the Arabic numerals of the EZM 13 never bothered me, but I can see the point of the criticism. A counter argument has been put forward to suggest that Arabic numerals would help an oxygen starved diver orient themselves to read the time under conditions of stress or reduced brain function. I wouldn’t know as I’m not a diver (currently), but I see that because most dive watches don’t have Arabic numerals, I can’t really accept this point.

Whatever the case may be, I would personally be happy with either one, old or new. But in a pinch, I would probably take the newer one.

Why the Sinn EZM 13.1?

If you’re familiar with the old EZM 13 you can probably stop here and just go on with your day, because everything about the new watch, aside from the dial, is exactly the same. If you aren’t then let’s continue to discuss what makes the new EZM 13.1 (for 2022) a compelling option for your wrist.

As I’ve mentioned before, the Sinn EZM 13.1 is one of the few watches on the market that you can buy now that allows the use of the chronograph function underwater. In fact, it's the most affordable out of the ones I mentioned earlier in my article, coming in at EUR 2,650 on leather or rubber straps to EUR 2,850 on a steel bracelet.

The movement is a Sinn modified version of the Valjoux 7750, called the SZ02, with the modifications including the removal of the 12 hour chronograph counter, and the change of the 30 minute counter to a 60 minute one.

This 60 minute sub-dial takes a large and central location above the 6 o'clock position on the dial and is much easier to read from a distance than the 30 minute chronograph counter of the typical Valjoux 7750. The watch of course measures only up to an hour, which is appropriate in a diving context, though it is possible, if you’re on land, to use the chronograph in conjunction with the diving bezel marking the hour hand instead of the minute hand, and use that to time periods longer than an hour.

Other notable features that showcase the focused attitude of its design include the date wheel, with red numerals against a black background, that recedes from view under low light conditions, a running seconds indicator at the 3 o’clock position, made very small and in gray, and only used, in the diving context, to show that the watch is running as per ISO6425 standards, a 60 click unidirectional bezel, as expected, an impressive 500 metres of water resistance and finally, 1,000 Gauss of magnetic resistance.

On that last point, it’s worth noting that the Sinn EZM 13.1 and its sibling the EZM 3 are the only two diving watches that the brand offers with magnetic field protection. The rest that do, as you would expect, are pilot’s watches. This is something to take note of if this feature is important to you.

Lastly, that left handed, or “Destro” layout of the crown and chronograph pushers, a Sinn signature move, helps in making sure that the controls of the watch do not interfere with your wrist during physical activity. Just to be clear on this then, you start and stop the chronograph with the lower pusher, and then you reset with the upper pusher.

Now regarding the underwater use of the chronograph pushers, I have to admit, I will find this a very difficult thing to do because of the psychological barrier that I have to overcome through years of training in this being precisely the thing not to do.

It helps that there is Sinn’s Ar-Dehumidifying Technology - a combination of nitrogen (previously Argon) gas in the watch that helps to trap any moisture and prevent it from interacting with the movement, as well as a copper-sulfate capsule that helps to remove any moisture that might come into the watch. This capsule is visible on the lug of the watch and starts as white, but turns blue as more moisture is absorbed over time. It’s a good warning system that helps to give me peace of mind if I decide to engage the chronograph underwater.

There is also Sinn’s D3 pusher system, which according to their website states that “In our D3-System watches, the push-piece pins and crown shafts are mounted directly in a fine-finished case aperture, creating a perfect seal to the case.” I’ll have to find out for myself how this works exactly, and what type of procedures Sinn has in place to ensure precise machining of the parts involved, but it should be interesting.

On the wrist

The watch wears surprisingly well and part of the reason why is that it has dimensions that remind me of Sinn’s original EZM 1 from 1997. That iconic watch was 40mm wide and 16mm thick which is near enough to the dimensions of the EZM 13.1 at 41mm wide and 15.4mm thick.

Because it is Valjoux 7750 based, the height of the case cannot be helped and you'll have to accept that it'll sit somewhat tall on the wrist. I wouldn't go so far to say that it's tuna-can-like in feel, but I can see where the comparison comes from. It helps that the lug to lug distance of 47mm enables the overall footprint to be tidy, with the rounded bulge of the case-back helping the watch sit into the wrist somewhat, taking away some of the bulk.

Generally speaking though, if you're used to wearing a watch with a Valjoux 7750, then the height of the Sinn EZM 13.1 will be a non-issue to you. But if you're used to a thinner three hander, a chronograph like the 12.2mm Rolex Daytona or even most vintage manual winding chronographs, then it's best to try the watch on in real life to see if you can live with the 15.4mm height on your wrist. I certainly can.

Lastly, the pushers have a decisive and positive feel, and surprisingly take less force to engage than a typical Valjoux 7750. The bezel action could be better, it’s not exceptional but it works.

Overall then, a good watch, but one major caveat - it doesn't have Sinn's ultra scratch resistant tegimented case, which is a bit of a bummer since quite a few of the rest of the EZM lineup do.

Sinn, if you’re reading this article, make an EZM 13.1 T. Do that and I’ll buy one. And oh, update the clasps of your bracelets with a micro-adjust capability while you’re at it.

Other options

If you’re like me and considering this watch among other similar candidates then here are my thoughts.

If your choice is between the EZM 13.1 and the EZM 1.1 or EZM 1, then the issue is whether or not you want a diving focused watch with a unidirectional diver bezel and 500m water resistance. Both the EZM 1.1 or EZM 1, while boasting a good water resistance of 200 metres, are not diving watches, as evidenced by the bidirectional countdown style bezel.

If your choice is between the EZM 13.1 and the EZM 1.1, then your points of consideration will include the sizes of both, their prices, and if a tegimented case is important. The EZM 1.1 is bigger at 43mm wide versus the 41mm of the EZM 13.1 with both being about the same thickness. The EZM 1.1 and the new for this year EZM 1.1 S are also more expensive, and difficult to get (both being 500 piece limited editions). But they are tegimented while the EZM 13.1 is not. Another point to consider is that some people like a running seconds hand on the dial, if that’s you, then it's the EZM 13.1.

If your choice is between the EZM 13.1 and the EZM 1, then the issue is being able to find an EZM 1, since it is long discontinued, and if you can stomach the prices nowadays since it is considered a rare collector’s item. If you want to use your watch as it was designed for, and not worry about wrecking an expensive and rare watch, then the EZM 13.1 is probably a better choice.

Conclusion

Overall then, the Sinn EZM 13.1 is an excellent choice to consider, especially so if you are after that mythical one watch collection. It’s an unflashy tool that tells the time, and gives you two methods of measuring elapsed time, and it even has a date. It can also be a trusty companion that can accompany you for all your adventures and missions in your life and for that I can’t think of any reason why it shouldn’t be on your wrist.

Technical Specifications:

SINN Movement SZ02
Self-winding mechanism
26 bearing jewels
28,800 semi-oscillations per hour
Seconds stop function
Anti-magnetic as per DIN 8309

Case
Case made of stainless steel, bead-blasted
Sapphire crystal glass in front, anti-reflective on both sides
Case back screw-fastened, nickel-free
Crown screwable
Meet the technical requirements for waterproofness, as set out in standard DIN 8310
Waterproof and pressure-resistant to 500 m diving depth (= 50 bar), certified by DNV
According to the technical demands for the diving norm DIN 8306
Tested based on European diving equipment standards EN 250 / EN14143 and certified by DNV
Low pressure resistant

Functions
Hours, minutes, subsidiary seconds
Date display
Chronograph with 60-minute stopwatch display
Diver’s bezel with minute ratcheting and luminous key mark

SINN Technologies
SINN movement SZ02 with 60-minute stopwatch display
Ar-Dehumidifying Technology enhances functional reliability and freedom from fogging
Temperature Resistance Technology, therefore functionally reliable at temperatures from -45°C up to +80°C
Magnetic Field Protection up to 100 mT (= 80,000 A/m)
Captive bezel
Push-pieces with D3-System

Dimensions and Weight
Case diameter: 41 mm
Band lug width: 20 mm
Case thickness: 15 mm
Weight without strap: 98 gramme

Dial and Hands
Mission timer design for optimal readability
Matte black dial
Indices coated with luminescent colour
Hour, minute and second hand coated with luminescent colour

Warranty
Warranty period 3 years

Well, I have to say, after seeing it in person a few times, this mother of pearl dialed diving watch will certainly be captivating to a male James Bond as well. Indeed I have come across this variant of the Sinn U50 three times already in the last few months on the wrists of two men and one woman. Clearly its appeal crosses gender boundaries as it is a beautiful watch in its own right. Hell, I’ve even told myself, after being mesmerized by a mother of pearl dial before in another watch, that this was a dial material that I had to explore for myself. 

Would the Sinn U50 S Mother of Pearl be that watch I would have to own? Clearly, I was thinking about it too much for my heart to ignore the possibility.

There’s no denying that the Sinn U50 is one of the brand’s best launches in recent times. It takes the best ingredients of their iconic U1 and downsizes it to a more manageable 41mm size and 11.5mm thickness for most wrists. It’s a winner and its popularity is evidenced by the fact that it is more expensive than the bigger and heavier 44mm U1 and that it is more difficult to get hold of at dealers worldwide. 

Using this model as a foundation for a variant with a mother of pearl dial then strikes me as a genius move. Sinn, of course, is no stranger to using this material – they currently have the 556 model in their catalog in two versions, either with a black or white mother of pearl dial as well as several ladies models. Those were more straightforward in their implementation however, with more of a dressy feel overall with traditional looking cases. The Sinn U50 S Mother of Pearl however is a study in unexpected contrasts since it’s not so common for such a delicate and romantic material, to be paired with a high performance 500m water resistant diving watch. 

The question I had then – would this watch be a winner for my wrist? Further, would I abandon my trusty and regular Sinn U50 for this special mother of pearl variant? I had to find out. 

Watch in hand

Before I begin, I’ll make this clear. The U50 S Mother of Pearl was only released last year (2021) as a limited edition of 500 pieces. As such there are only a handful of pieces around the world at dealers that you can still buy new. This will most likely get harder to do as each day goes by. Online response to this watch has been exceedingly positive, and the remaining pieces will get snapped up pretty quickly. Your best option therefore if you miss out is to buy used, but again you’ll have to be ready to jump on it if you see it for sale, as you will find, as I did myself, others competing with you to buy the same watch.

Now with the main appeal of this watch being all about the dial, there’s really no need to spend too much time on the characteristics of the U50 family of watches. I covered my thoughts on the models in a previous article you can read linked below. This mother of pearl version though, unlike the tegimented variant that I wrote about, comes with an additional layer of black hard coating (PVD) over tegimented steel, which effectively raises the surface hardness rating of the watch to a staggering 2000 Vickers, which make it as scratch resistant as ceramic. 

While I haven’t had enough personal experience with Sinn’s PVD coated watches, I can say that my tegimented Sinn U50 has not picked up any marks in the time I have had it, so I have no reason to doubt Sinn’s claims. 

The dial – What can I say? It’s so beautiful, you feel like you’re staring into the ocean. It is the kind of dial that you can just stare into and forget about checking the time. In bright sunlight, the dial explodes with colors akin to the aurora borealis. With light coming from various angles, you are treated to a shimmering explosion of blue and purple hues. The experience is simply amazing. 

Why this happens is because the individual aragonite plates that make up the “nacre” (an old name for mother of pearl) are small enough such that they break up the visible spectrum of light into shorter and longer wavelengths, making it change colour depending on the angle you look at it. 

You’ll know how magical this effect can be if you’re an aficionado of mother of pearl, and can probably remember the moment you became one – when a dial you once saw a long time ago captivated you. 

Accentuating the mother of pearl dial there is also the black case and black bezel with its engraved markings filled with a matching bluish/ purple paint. 

The fact that mother of pearl is a natural material is also what makes every dial unique, (as is your number among the 500 piece limited edition). This is a good thing because you learn over time to recognize the intricate details of your own watch. 

But this can be a double edged sword. While five of the examples I’ve come across are attractive, I’ve actually seen one that wasn’t so nice as it had a wart-like protrusion near the date window. I had to reject that piece for consideration as it was just too ugly. Regarding mother of pearl dials then, Its best to be able to see the watch in person before you buy, or if not, to request pictures of the specific watch from sale from the seller. This is important so that you can determine if the look of the dial makes you happy, and more importantly, if it disturbs you if it is ugly since you have to look at it every time when the watch is on your wrist. 

So, having acquired this particular example of the Sinn U50 S Mother of Pearl, why did I start to have mixed feelings about it? 

A tool watch for tools?

Let me start by first saying this – I don’t understand why black lume was invented. The main reason probably is for aesthetics – you want to have black hands and hour markers on the dial in normal light, yet still be able to read the time at night even though it performs so poorly that the black lume might as well not be there – but better than nothing I suppose. 

You’ll note that the hour, minute and seconds hands, as well as the hour markers, of the Sinn U50 S Mother of Pearl are all black. It is said that they are coated with black lume, which it clearly is since they glow when exposed to UV light. Yet it does this so poorly that I wonder why they even bothered with it.  

Obviously, as it is a diving watch there has to be some provision for visibility at night, which is in my opinion a flimsy justification to use the black lume. Just look at this picture here, I did a comparison of the longevity and brightness of the black lume compared to that on the standard U50. It’s disappointing. It’s not even close. 

The thing is, we all know that Sinn makes tool watches. In fact, they make the finest tool watches I have ever experienced. To this end, I wear my regular Sinn U50 when I have to do things that might put my normal watches in harm’s way. In all the time I have used the watch while underwater, at night, or during intense physical activity, legibility has never been a problem. 

Those thick hour and minute hands, with their funky Lego block design that might divide people’s opinions on their attractiveness, were designed that way for a reason. They are the reason why I can read the time all the time, and I can even give someone the time, who is standing three metres away in the dark, by telling them to look at my watch. 

Clearly I have been spoiled by the standard U50, the most legible watch I’ve ever owned bar none. 

The Sinn U50 S Mother of Pearl when compared to the normal Sinn U50 – well they’re not even in the same league.

With black hands and black hour markers coated in barely glowing black lume against a dial that is as reflective as a mirror, you’ll be able to read it in situations when there is adequate light around. When the evening comes though, and the ambient lighting levels start to go down, you can have a bit of a problem. Even if you use a UV torch to charge the lume, or walk into a dark place from bright sunlight, it’ll only be a short time before the watch becomes barely readable again. 

Well, wasn’t this watch supposed to be a functional tool? While the dial certainly makes it special, I cannot help but wonder why, in the context of the Sinn brand and the U50, this watch was created. 

Was I experiencing an existential crisis? 

Making peace with beauty

Given that it is time that a watch measures, it is fitting as well that it is through time that we form a better understanding of our situation, no matter what it is. Having been provoked by these thoughts on why a watch like this could be allowed to exist, I put it away, and decided not to think about it too much. 

Again and again though, I would retrieve it from its case, put it on, and find myself smiling as I enjoyed the intricate details of the mother of pearl dial. 

Somehow this was a watch that I could not let go. 

As my thoughts on it started to coalesce and I began to calm down, I started to form a new idea about what this was all about. I think that one should consider this watch to be a piece of art rather than as a functional tool. It was made after all around a beautiful idea.

Just think about it. When I look at this watch I see the beautiful imperfections of nature standing in stark contrast to the utilitarian purpose of its foundation. What does this combination allow one to do? Well, to bring the mother of pearl into the environment it originally came from – the deep blue sea.

Try doing that with most watches with mother of pearl dials that are more dress oriented. 

The best thing to do then is to have both for different situations. Sometimes, I have to admit, I have found the standard U50 a bit too stark, too severe and too purposeful. Those lego block hands that impart a playful albeit functional touch do give it some personality, but given that it’s a baby U1, the toolish nature of the watch is still evident. 

Not so with the U50 S Mother of Pearl. Sometimes you want to have some romance and beauty in your life. Sometimes you want that artistic statement that can come from the contrast between the utilitarian U50 and that beautiful mother of pearl dial. The art comes from it being a combination that doesn’t make sense, and that is somehow irresistible. 

My conclusion therefore is that this is the ideal watch to wear when the stakes are not high. For example, as a vacation watch it is something beautiful to look at, yet functional enough that you can go into the sea with it and do what you need to do, having great adventures while it accompanies you, and not being left on the surface where it could get stolen. In a pinch, just bring a torchlight, which you should already have with you when diving, and throw some light on the dial to read the time if you really need to.

But I will say this – if the stakes are high, and I won’t know what the conditions will be like where I will take my watch, or if I’m James Bond on a mission and need to survive, I would most probably take the normal Sinn U50. 

PS: my friend Tim helped compose this short poem about the watch:

Great on a date /But not too late /Bring it to bed/ It can’t be read

Technical Specifications:

Mechanical Movement
SW300-1
Self-winding mechanism
25 bearing jewels
28,800 semi-oscillations per hour
Seconds stop function
Anti-magnetic as per DIN 8309

Case
Case made of German Submarine Steel
Sapphire crystal glass in front, anti-reflective on both sides
Case back screw-fastened
Crown screwable
Meet the technical requirements for waterproofness, as set out in standard DIN 8310
Waterproof and pressure-resistant to 500 m diving depth (= 50 bar), certified by DNV
According to the technical demands for the diving norm DIN 8306
Tested based on European diving equipment standards EN 250 / EN14143, certified by DNV
Low pressure resistant

Functions
Hours, minutes, seconds
Date display
Diver’s bezel with minute ratcheting and luminous key mark

SINN Technologies
Black Hard Coating on a TEGIMENT Technology basis
Captive bezel

Dimensions and Weight
Case diameter: 41 mm
Band lug width: 20 mm
Case thickness: 11.15 mm
Weight without strap: 74 gramme

Dial and Hands
Shimmering black mother-of-pearl dial
Indices coated with luminescent colour
Hour, minute and second hand coated with luminescent colour

Limited to 500 pieces

The appeal is easy to understand- at its core, the Sinn U50 is a good watch at a good size, and all it took was a very simple formula – take the performance capabilities and styling of the brand’s iconic 1000 metre water resistant U1, and shrink it down from 44mm to 41mm, (with a halving of the water resistance to 500 metres and corresponding required case thickness) and thus you have the U50.

For those who wanted the U1 but held back because of its biggest downside – the size, Sinn basically removed all objections to buying the watch by creating the U50, and because of this it has shot to the top of the list for those who want a capable everyday diver with Sinn’s unique technologies packed in.

The Sinn U50 basically offers everything good about the U1, including the unique handset and dial design that is immensely readable under all conditions, (despite some naysayers suggesting that it looks too toylike). As well, Sinn has offered the U50 in a dizzying array of configurations at launch including with a standard submarine steel case or tegimented, the bezel in tegimented steel or SDR black, and on either a tegimented bracelet or rubber strap. Such a wide array of options will make fans cheer, since this is a similar way that the U1 is offered. Take your pick depending on your budget or your preference. Either way, Sinn’s got you covered.

With my generally positive opinion on the U50, did I come across any negatives?

Well, let’s start with my first impression of the watch. It’s not a negative per se, but if you’re coming from the U1 or Sinn’s other large tool watches, you might find that when you’re trying the watch on for the first time that it feels too small. Don’t let this illusion fool you. The U50 is similar in size to a sports Rolex, and in use everyday the size will be perfect. If you’ve been acclimated to a larger watch and are looking for something that is lower in profile and doesn’t snag on objects in the environment, then this is the watch for you. Dimensionally the U50 is 41mm wide measured at the bezel’s edge, which sticks out a little over the actual footprint of the watch on the wrist and so does wear smaller. Additionally it is 11.3mm in thickness versus the 14.7mm of the U1, so there’s a big difference in weight and comfort.

Now loose bezel play is something that has been mentioned before in relation to Sinn’s watches and it is the same with the U50. There is a slightly imprecise feel to the action, and it’s not as crisp feeling as what you might expect. I used to be bothered by this, but the explanation I’ve been told is that it’s made this way so that it is easy to turn under all conditions. In my time with the watch, this has proven true. I’ve taken the watch swimming in fresh and saltwater, and have always found the bezel easy and able to turn even with wet or gloved hands. From a performance standpoint then, it’s engineered well, and for real conditions, and in this respect, Sinn has made the right choice.

Then there is the issue of the lume that many have criticized isn’t as strong as it should be when compared to others. Again Sinn has a performance related explanation and it seems that it’s a formulation that emphasises longevity over brightness.

This watch might not dazzle the eyes when you’ve blasted it with a 1000 lumen torch, but on a recent trip to the Singapore Night Safari, in which I took a 40 minute train ride through the park under barely visible conditions, the watch remained supremely legible the whole time and at all angles. The lower intensity I gather also works well when your eyes have adapted to dim light, and so to Sinn’s credit, it’s another performance related decision that works.

At this point you might consider that I might be sounding like an apologist for the flaws of the U50, but I do have some misgivings.

The first aspect is the crown at the 4 o’clock position. Now it is good that it is there since it is out of the way and more protected than by being at the normal 3 o’clock position. This crown however is too small, and very difficult to adjust. The tegimented coating also makes it a little too smooth and difficult to grip. This is similar in my experience to the Sinn EZM 12, and I’m really not sure how to solve it. Perhaps the crown can be made bigger, but there doesn’t seem to be any space since it’s so close to the lug.

On this,I console myself by telling myself that I don’t need to set the time often, but I have to say, when I pick up the watch after it has stopped, I don’t look forward to setting the time again.

The next major bugbear I have is with the clasp. Now I would be a little less harsh on many other watch brands if they had a clasp like the one on the bracelet of the U50, but this is Sinn we are talking about, with magic engineering skills to do things that others can’t. In this regard I cannot forgive the dated design, which seriously needs an upgrade. More worryingly, when I was wearing the watch, the clasp, even with its foldover lock, has opened by itself at least three times, and on all these occasions on just the lightest touch of an armrest or table top.

Luckily the watch did not fall from my wrist, but I would like to urge Sinn to do something about it.

What’s my conclusion then? Well, despite the flaws I’ve mentioned, this is a watch that has managed to find itself on my wrist time and time again. Performance capabilities aside, it is something I put on when I foresee some possibility of intense activity where I would need a watch that can hold up and take care of itself. Best of all, it doesn’t have that squint and you might mistake it for a Submariner look that is prevalent among dive watches.

Specifications

Movement: Sellita SW300-1, Automatic, 28,800 semi-oscillations per hour, Hacking seconds , Anti-magnetic as per DIN 8309

Case: German Submarine Steel, bead-blasted, Sapphire crystal glass in front, anti-reflective on both sides
Case back screw-fastened, Crown screwable, Waterproof and pressure-resistant to 500 m diving depth (= 50 bar), certified by DNV according to the technical demands for the diving norm DIN 8306, Tested based on European diving equipment standards EN 250 / EN14143 and certified by DNV, Low pressure resistant

Functions: Hours, minutes, second, Date display, Diver’s bezel with minute ratcheting and luminous key mark

SINN Technologies: Bezel with TEGIMENT Technology, therefore especially scratch-resistant, Captive bezel

Dimensions and Weight: Case diameter: 41 mm, Band lug width: 20 mm,, Case thickness: 11.15 mm, Weight without strap: 74 gramme

Dial and Hands: Matte black dial, Indices coated with luminescent colour, Hour, minute and second hand coated with luminescent colour

144 St S Anniversary II

The 144 is a model that has been in the Sinn catalogue since 1974 and has seen many technical upgrades over time, for example sapphire glass for the crystal these days instead of mineral glass as was common then.

The latest Anniversary version for 2021 comes with the full suite of Sinn technologies such as 200 metre water resistance, Ar-Dehumidifying technology, and a 41mm wide tegimented case topped with a black hard coating.

Aesthetically, this watch also distinguishes itself from past models with white chronograph counters as well as a red “60” at the 12 o’clock position, both to represent 60 seconds of elapsed time as well as a subtle nod to the 60th anniversary year that the watch appears in.

Limited to 600 pieces, the144 St S Anniversary II comes with both a bracelet and a black silicon strap in the special box set, so you can make your choice of which to wear after you’ve bought it.

104 St Sa I MG with green dial

The new 104 St Sa I MG, as Sinn admits unapologetically, goes along with the trend for green dials these days and dispenses with the typically sober and serious character of a serious pilot watch, opting for a burst of colour. The green dial is painted in a metallic finish, like that used in car paint, and has a textured look at angles even though the surface of the dial is smooth.

There is no limitation on this model, and aside from the new dial colour, it comes with all the standard specifications that you’d expect, such as 200 metres of water resistance and the captive (secured with screws) pilot style bezel with minute ratcheting in a nicely sized 41mm case.

358 Sa Pilot DS and 358 Sa Pilot B E

The 358 is a well loved staple model in the Sinn line-up and represents Sinn’s idea of a traditional pilot chronograph at 42mm in diameter. Two new non-limited versions come to the catalogue this year, that add an aesthetic flourish to a technically competent platform. The first one, the 358 Sa Pilot DS comes with a dial that features decorative grinding, just like the one seen on the dial of the 60th Anniversary Sinn U1 DS, a model that was launched in the early part of this year. This is a dial treatment that is technically demanding to execute by hand, with special training required in order for the right amount of pressure to be applied. Each dial by necessity is a unique piece, since the pattern of scratching will vary.

The next variation is the 358 Sa Pilot B E, which comes with a dial in galvanic blue with a sunburst decoration. Both models come with a domed sapphire glass, a nod to the aesthetics of vintage mineral glass of old. Lastly, the watches offer 100 metres of water resistance and Ar-Dehumidifying technology.

U50 S Mother-of-Pearl S

The U50 has definitely gotten some amount of attention since it was released not too long ago. It’s clear that there has always been a demand for a watch with the strength of performance of the U1 but at a smaller size. The U50 has, at 41mm, definitely opened up the U series to those wanting a smaller watch but with serious technical specifications. With the new U50 S Mother-of-Pearl S, it might just be that Sinn are responding to possibly more women coming to the U series since the introduction of the U50.

The mother of pearl dial of the U50 S Mother-of-Pearl S definitely fits in with the aquatic theme of the watch. Aesthetically, given that the mother of pearl is the only reflective surface against a black case and black indices, it does become the centre of attention. Add in the black background of the date numerals, and it seems to be a fitting piece for a female James Bond, that needs something a bit showy, but with black indices that will still glow in the dark, and overall proper diver functionality.

Limited to 500 pieces with all the Sinn goodies that are standard in the U series, such as tegimented submarine steel with a black hard coating.

Model 717

The new 717 is a central minute and central seconds chronograph inspired by the Nabo 17 ZM cockpit clock with central minute counter that was originally designed for the German Luftwaffe’s Tornado program.

Easily one of the highlights of Sinn’s launches this year. The design of the 717 deviates very slightly from the Nabo 17 ZM with pretty much the same complication, a running seconds sub dial and even the use of Arabic numerals.

Taking advantage of the in-house SZ 01 movement, a Sinn modified Valjoux 7750, this 60 minute chronograph counts both minutes and seconds from the centre of the dial, making elapsed time extremely fast and easy to read under extreme conditions. It’s a movement we’ve seen before in the EZM 10 and the EZM 1.1, and was developed by Sinn due to the discontinuation of the Lemania 5100 that was also famous for having a central minute chronograph.

Aside from this movement, the Model 717 also replicates the chapter ring of the Nabo 17 ZM, but makes it rotatable as well as an additional pilot style bezel. Lastly the case is tegimented with a black hard coating, and also comes with Ar-Dehumidifying technology.

At 15.3mm thick and 45mm diameter, this is one large and useful watch that gives pilots or wannabe pilots one more option to consider besides the amazing EZM 10.

The first model to be launched was just announced via a digital press conference today, and it is the new Sinn U1 DS, a fully tegimented diver made of the brand’s signature German submarine steel, but with a unique dial. 

The clue is in the name – “DS” stands for “Dekorschliff”, a German word that roughly translates to “Decorative Grinding/Polish”. This is a new type of finish that is applied to the raw brass dial, which is galvanically treated twice before being hand scratched in random patterns to give an aged, weathered look. 

Lothar Schmidt, Sinn’s Owner and General Manager, explained that the unique look had come about from a series of experimentations, to find new dial possibilities. This was one of the options that came from that process, and while the end result was beautiful, remarkable and very special, the company took some time to adjust to the idea of such a dial in a Sinn product. It’s easy to understand why given the austere, serious and technical character of the brand, but eventually they decided to go ahead with it. 

If you think you’ve seen this type of dial finishing before you would not be wrong, as it has appeared in another watch that came out two years ago, the 356 pilot chronograph that was created in collaboration with Singapore watch retailer, The Hour Glass. 

That being said, the new Sinn U1 DS is the first appearance of this type of dial within Sinn’s own product family, and it was chosen to be done given that it would not affect the technical function of the U1, which is Sinn’s premier and most iconic diving watch capable of 1000 metres of water resistance.  

Legibility is maintained with the all white markers and hands, and even the bezel markings. The entire watch is monochromatic, and stunning, without a hint of colour as might be expected, yet it is uncompromised in its function as a diving instrument.  

The ingredients of the Sinn U1 DS are to be expected. It comes with an in-house made (in the company’s Glashütte facility) fully tegimented, case, bezel, bracelet, clasp and crown, which is Sinn’s proprietary surface hardening technology that makes the watch scratch resistant to 1500 Vickers. This treatment is applied to all the parts of the watch made out of German submarine steel, a material that is, because it is used in submarines, is totally non-magnetic, and able to resist deformation pressure and tearing. Because of its strength, it is used in all U series watches, and can easily withstand 1000 metres (+25%) of water pressure. 

The fact that the case is so strong and that it is scratch-resistant, is a somewhat interesting contrast to the fact that the dial is scratched, which does make the U1 DS seem a little playful in concept. Not too far though – it’s still a Sinn after all. 

The watch is powered by the Sellita SW200 automatic calibre, with 38 hours of power reserve and with Sinn’s own proprietary oils. Round the closed caseback there are no engravings to suggest that this is a 60th Anniversary edition, but there is an engraving of the limitation number, out of 500 pieces. 

All in all, it’s a cool new addition to the collection, and what’s interesting is how in such a serious instrument like this, there is an extra touch of a hand-crafted dial. As explained by Sinn, there is an element of skill involved in creating the dial, with special training required. The reason is that the scratching cannot be applied too deeply on the dial during the roughly 5 minute process, and a consistent pressure is required by the craftsman involved to maintain the look and style of the scratches over 500 watches.

It’s a great first start to 2021 for the brand, and I am told that the next big launch will come on April 1st 2021. In the meantime, have a look at the technical specifications of the new watch below, done in the detailed manner that Sinn is famous for.

Mechanical Movement

• SW 200-1
• Self-winding mechanism
• 26 bearing jewels
• 28,800 semi-oscillations per hour
• Seconds stop function
• Anti-magnetic as per DIN 8309

Case

• Case made of German Submarine Steel, bead-blasted
• Sapphire crystal glass in front, anti-reflective on both sides
• Case back screw-fastened
• Crown screwable
• Meet the technical requirements for waterproofness, as set out in standard DIN 8310
• Waterproof and pressure-resistant to 1,000 m diving depth (= 100 bar), certified by DNV GL
• According to the technical demands for the diving norm DIN 8306
• Tested based on European diving equipment standards EN 250 / EN14143 and certified by DNV GL
• Low pressure resistant

Functions

• Hours, minutes, seconds
• Date display
• Diver’s bezel with minute ratcheting and luminous key mark

SINN Technologies

• TEGIMENT Technology, therefore especially scratch‑resistant
• Captive diver’s bezel

Dimensions and Weight

• Case diameter: 44 mm
• Band lug width: 22 mm
• Case thickness: 14.7 mm
• Weight without strap: 113 gramme

Dial and Hands

• Dial with decorative grinding
• Indices coated with luminescent colour
• Hour, minute and second hand coated with luminescent colour

Warranty

• 2 years

Specifically of course, this is a watch that was designed and made for helicopter emergency rescue doctors and comes with a set of features that are well suited for members of such a profession. Along with its tough (tegimented) stainless steel case that is 200 meters water resistant and anti-magnetic (important for an aviation watch), the medical features on board include an inner and outer bezel (for measuring platinum ten minutes and golden hour), and a four bladed seconds hand used in conjunction with a pulsometer scale to measure pulse, that only requires a 15 second interval before a pulse can be measured. Even the case is designed in such a way that it will not snag on rubber gloves, with every surface designed to be free of sharp edges. Lastly, the straps and bezel can be removed from the case quickly and easily for disinfection. 

The 10-minute interval or the platinum ten, is a concept familiar to all types of emergency rescue and ambulance crews and is the period during which emergency crews, upon their arrival at the scene, assess the situation and initiate treatment and transport of casualties. The golden hour, also known as golden time, is the period of time following a traumatic injury during which there is the highest likelihood that prompt medical and surgical treatment will prevent death. These are the aspects of time that are crucial for a doctor to be aware of in an emergency, and they are accounted for in the inner and outer bezel design of the EZM 12.  

While you can buy one to wear if you are a land based doctor or paramedic or even want to pretend to be one of these medical professionals, I think that to properly evaluate how useful a watch like this is for its intended purpose, one really has to speak to a real helicopter emergency doctor. 

Enter Martin Leitl, one of the helicopter emergency doctors who was invited to test the watch in its development. You can find out more about his background from this article on the Sinn website and this one from his personal website.

What are the unique skills that an airborne emergency doctor has to have compared to those who are ground based?

Basically we both need the same skills concerning medicine. Most emergency doctors start on the ground in an ambulance and then, if possible, they switch to the helicopter. The additional skills depend on the area/region where the rescue helicopter is based – as it could be near the sea or like where I’m from in Switzerland, close to high mountains. 

For me, I have to be able to move and work under mountain conditions, and to be familiar with dealing with snow and rock. For complex rescue missions, an additional mountain rescue specialist joins the crew to go in with the doctor (or alone) to get to the patient and to take care of the safety of both patient and doctor.

Can you give me examples of what are the most serious medical emergencies you have encountered in the mountains?

Here, around the high mountains of the famous Eiger, Mönch and Jungfrau we have to take care of avalanche victims, accidents in the ski areas, mountaineers who were hit by falling stones or who fall from the mountains, and of course there are injured para-gliders and sometimes very severe injuries of B.A.S.E jumpers and wing-suiters.

I read that at the age of 16 you became an active member of the Bavarian Red Cross Mountain Guards where you started your first training in first aid and mountain rescue. What aspect of this experience made you want to become a doctor? 

As I love mountains and outdoor sports I know what can happen there and how lucky someone is to get medical help. So it was not a far step for me to join the Mountain Guards where I first learned about medical issues and rescue tasks. I was also interested in the world and conflict areas in the world – I don’t know why exactly. But I wanted to go out there to work in these areas to help the victims and also to learn about the problems and conflicts in the world. This is why I joined “Doctors Without Borders” (Médecins sans frontières).

What specific medical training is necessary for mountain medical emergencies? 

Doctors must be trained in emergency medicine and in addition to this have experience in mountaineering. There are mountain medicine courses (winter and summer) which also include training in technical issues of mountain climbing. And of course we get special training with the helicopter to be able to do a long line rescue.

Tell me if you have used the special features of the EZM 12 in an actual emergency scenario?

I always use the special features on my missions: I set the inner bezel at the time when I get to the patient to know how long I am already with him. The outer bezel I use to mark the time when I give certain drugs, for example, Fentanyl, which is a strong opioid against pain. Before switching to the EZM 12 and also during my first mission to Antarctica, I used the EMZ 10. With that watch I started the stop function when I arrived at the patient and used the outer bezel to mark the time, when I gave a special drug. The EZM 12 replaces the more complex chronograph function of the EZM 10 with its inner bezel.

Do emergency doctors actually use a pulsometer?

Well, we always have a small electronic finger-clip pulsoxymeter with us (see below) and of course a proper ECG/monitor/defibrillator for severe cases) in the helicopter but also to carry along (but heavy). So for “normal” cases we use the finger-clip pulsoxymeter.

The pulsoxymeter shows us the heart-rate and the oxygen saturation of the blood very quickly.  But you never know. Sometimes these electronic instruments don’t like harsh conditions like low temperatures, and so the EZM12 with its pulse rotor is a nice feature to have as an overview over a patient’s heart rate. I also really like it because it gives the EZM12 a special helicopter touch.

You mentioned in the article that you appreciate mechanical watches, which is why you appreciate the EZM 12. What other watches do you own or admire?

Well, the first mechanical watch I bought was the EZM 10. I choose it because it is also really made for harsh conditions so I was happy to wear it when I was joining the first scientific expeditions in the Antarctic. Then the EZM 12 came out and I had the honour to test it and I really liked all the special features that it had that were designed for an emergency doctor. The most unique thing about the watch is the fact that you can easily clean and disinfect it with the easy to remove strap system.

In general there are of course other nice mechanical watches but I like Sinn watches also because of the materials they use: I enjoy the titanium of my EZM 10 because it is so light-weight. One day I may have a look at the elegant classic pieces from the Sinn collection – maybe when I get married.

For my work as mountain guide, I of course use a digital watch with altimeter and GPS – it is a Suunto Traverse. (pictured above)

What attracted you to the EZM 12?The design is puristic and very durable and still it contains the most useful features for my work. And it is water resistant – as we are working  in all weather conditions

What features of the EZM 12 do you find most useful?

The medical based features such as the inner and outer bezel, and that it is easy to clean and disinfect. Also the watch and strap on the wrist is very comfortable.

Do you wear the EZM 12 everyday or only when you are in the mountains or expect to encounter tough conditions?  

I wear it on my rescue missions, during my work as a general practitioner in a walk-in-clinic and as an every day watch as it looks very sporty. I don’t wear it during my work as mountain guide (as I need a watch with altimeter and a clock and GPS for emergencies.

Is there anything that you would tell Sinn, based on your experience with the watch that you would improve in a possible next version of the EZM 12?

No, it is really a cool watch. They developed the watch with the advice of an airborne emergency doctor and this you really can feel. It is made for this job.

Sinn has produced a really interesting brochure that details the special features of the EZM 12. It’s worth taking a look. You can download it here.