Owner’s Review: The Sinn U50

This review is written from an owner’s perspective. There will be bias. 

When Sinn revealed the U50 earlier this year, a much wider audience than the German brand usually taps into stopped and took notice. The watch represented their trademark diver aesthetic popularized by the U1, packaged in an approachable 41x11mm case at an accessible price point around $2,000. This was the watch many of us had been asking for, and Sinn delivered the goods in spades. As the U50 began to ship over the summer, I took the opportunity to add one to my own stable, having long been a fan of the blocky yet modern design, but never quite able to pull off the bulkier dimensions of the U1. In many ways, this is a watch that lives up to the hype, and whose success could signal a broader sea change in the genre.

Sinn U50 T and U50 SDR

You’ve likely noticed a trend that’s taken hold in much of the industry in which brands are resurrecting references from their back catalog, releasing their greatest hits with modern movements and better build quality. Buyers and enthusiasts, myself included, have celebrated this return to what many of us see as the glory days of watch design. Looking back at watches from the ‘90s and early ‘00s it’s not hard to see how we ended up here. Past attempts at novel designs left many of us waxing nostalgic, and the past 10 years have represented a return to the ‘60s and ‘70s aesthetic, including pre-aged lume, should you desire. If you’ve found yourself asking ‘where do we go from here?’ in recent years, you’re not alone. 

One of the reasons we love small independent brands around here is their ability and willingness to exercise a greater degree of creativity in their products. Brands like Halios, Farer, and Autodromo (among many others) are carving their own path, with wholly unique design language, and the general watch buying population is taking notice. Larger brands should be as well, even if their ships are harder to turn. This is the world in which Sinn finds itself at present, and while they have considerable heritage, they aren’t quite a household name (save for your household, dear reader).


Owner’s Review: The Sinn U50

Stainless Steel, Bead Blasted, TEGIMENT Available
Sellita SW300-1
Matte Black
Flat Sapphire
Silicone Strap and Steel Bracelet
Water Resistance
Lug Width
Screw Down
2 years

Historical Context

While Sinn does produce modern timepieces, both in their aesthetic and their production, they boast a history that dates back to 1961. It is here that flight instructor Helmut Sinn begins selling cockpit clocks and pilot chronographs directly to the end users, bypassing retail sales altogether. Helmut sold the company to engineer (and former IWC employee) Lothar Schmidt in the mid ‘90s, but their watches, then and now, have retained their distinct sense of purpose built tools. The brand’s impressive array of certifications from the likes of DNV, ISO/DIN and TESTAF are testament to their unique abilities to survive and indeed persevere under extreme conditions (see EZM watches). We see the fruits of these advancements in technologies like DIAPAL, TEGIMENT, and Ar  (to name just a few) at use throughout their collection today. 

The Sinn U1

Sinn introduced their modern dive watch template with a watch called the U1 back in 2005 (see Zach’s review of the U1 here). This watch has been something of a standard bearer in dive watch circles thanks to its no frills presentation and blocky dial features. Its 44mm case is made from German submarine steel that’s been bead blasted for a uniform matte presentation, no polished chamfers in sight. It also enjoys TEGIMENT technology (more on that later) and is pressure resistant to 1,000m as certified by DNV GL. It’s a lot of watch presented in typical German fashion, straightforward with just enough personality shining through in the functional design elements.

As capable as the U1 is, its dimensions have made it an outlier on the periphery of more casual, everyday dive watches. Though 44mm is not extreme, it pushes the envelope just enough to remain more of a curiosity than daily wear candidate. Enter the U50, a watch released this year that captures all of the unique character of the U1, along with much of its diving capabilities, and packages it into a slim, 41mm case. We’re now presented with a watch that makes a great deal of sense in everyday use, and further still, expands our contemporary options in a genre rife with throwbacks.

The Sinn U50

The U50 presents much the same as the U1, and that’s not a bad thing. Every component seems to have its own personality to enjoy, and rarely do such watches bring each of these together in a harmony this successfully (the Seiko SPB149, reviewed here, is another such example). At a glance, the watch is almost brutal in its execution, but the proportions of everything rein the drama in, and on the wrist it becomes rather simple (enjoyable, even) to digest. A closer look will reveal why. 

Sinn U50 T on black silicone strap

The dial of the U50 will stand out in a crowd on account of its rectangular vital components, i.e., the hour markers and hand set. Each hour plot gets its own rectangular application, with the 6, 9, and 12 markers standing a bit taller than the rest. The date window at 3 (which is dial colored, by the way) keeps that marker sized uniformly with its neighbors. The hands stand out like tall buildings moving around the matte black dial, as stark white rectangles with red applied at their bases. Small protrusions at their tips (again, rectangles) allow for more precise measurements of the time. The seconds hand is entirely red save for two white lume applications at its tip. A minute track sits at the dial’s edge, neatly enclosing all of the above. Dial signage is kept to a minimum, with the Sinn mark in white at the top, and the model designation along with the words “Automatik” and “500m/50bar” appearing in red at the bottom.

The dial is the same on each variant of the U50, however the bezel, case, and bracelet can be optioned. The bezel on each example is hardened with Sinn’s TEGIMENT technology, which raises the strength of the base metal significantly, thereby bringing a greater level os scratch resistance to the most exposed part of the watch. The bezel can be had in black on the U50 SDR or steel, which is the standard U50. Likewise, the case is offered in a TEGIMENT variant in standard and SDR guise, as well as in full flat black as the U50 S. Regardless of choice, the bezel is unique for a few reasons. It sports wide, shallow grooves at its edge for easy handling. Manipulating is easy and satisfying, with hard yet muted clicks across each of its 60 stops, with very little play in between. Arabic numerals are present at each 5 minute increment, with minute demarcations running around the entire bezel, making them redundant to the dial. The first 15 minutes of the bezel also get half-minute marks for more precise measuring. Also of interest, the bezel itself is not friction fit, but rather is captive, affixed with the help of 3 small but visible screws along its side. It’s a solid piece so no insert is present. 

The hardened bezel of the U50

The case of the U50 is uniform in texture thanks to the bead blasting treatment, which also extends to the bracelet. It’s soft to the touch and visually distinctive in how it captures light, which is to say, diffuse. The lugs gently slope away from the case and are broken by hard lines at their edges. They are also drilled, making strap changes a breeze, and trust me, you’ll be tempted a plenty as this is a watch that welcomes any strap you’re bound to throw at it with ease from a visual standpoint. Time to let your NATO collection shine.


I find the bracelet to be the least successful part of the U50, and that’s not due to the design (which is subjective), but rather the clasp. From a design standpoint, the “H” links and floating square mid sections are unusual but work well with the whole from a visual perspective. The clasp itself is less than confidence inspiring as it requires a firm push to seat itself properly, and you’re not greeted with a reassuring ‘click’ when this happens, but rather with a muted slide which will have you double checking that it’s actually in. These are tricky to get right, and I don’t fault Sinn for what I see here, especially at this price point, but there are certainly better bracelets out there. 

U50 SDR on steel bracelet

On the other hand, the silicone option is sublime. It’s soft to the touch but firm on the wrist, and brings an excellent hardened clasp to the party. The play is smooth and the seating is on point here. Unless you’re a die hard bracelet person, this is the route we’d recommend. To my eye, it provides a welcome contrast with the steel bezel on the standard U50.

The excellent silicone strap

On The Wrist

The U50 is a joy on the wrist. The 41mm case diameter measurement feels generous, and had I slipped it on without knowing, I’d have sworn it was 40mm. It wears smaller than a modern Sub (for reference, see the U50 case side by side with that of a 114060 in the gallery below), feeling similar to those of the 4 and 5 digit variety thanks to the much slimmer lugs. Better yet, the case measures a hair over 11mm in thickness, and 47mm from lug to lug, and it’s those last two numbers hitting the sweet spot that make this watch so effortless on the wrist. As you’ve likely heard many times by now, the lug to lug measurement provides a more accurate depiction to how a watch will wear than the diameter alone. Lugs matter, people. 

Nothing to complain about here

The prominent fixtures on the dial make for quick and easy time reading, while the crown placement at 4 o’clock keeps it out of the way during activities. Lume is adequate as well, though it doesn’t last quite as long as I’d like. This is about as drama free as you’ll find when it comes to dive watches, and I suspect why the watch is in such high demand at the moment. These are the qualities other brands should be paying attention to, and the fact that you have to come to sites like this to find a lug to lug measurement is part of the problem. This should be standard reporting practice and I hope to see brands take notice.

11.3mm in height on the wrist


At the heart of the U50 resides the Sellita SW300-1, a Swiss automatic movement that stacks up nicely against the likes of ETA’s 2892 caliber. The caseback is closed so you’re saved a view of this unglamorous workhorse, but timekeeping is bang on within 5 seconds a day in my experience. There’s 42 hours of power reserve on tap, the seconds hack, and it’s even anti-magnetic to DIN 8309 standards. It has got you covered where it counts, as they say.

The crown at 4 o’clock

Winding and setting is smooth and drama free via the crown located at 4 o’clock, which is simple to manipulate if a touch on the small side. The SW300-1 is a scant 3.6mm thick (a full mm thinner than the Sw200, for those keeping track), which Sinn took full advantage of in their case design.

Price and Competition

The U50 can be had for as little as $2,180 for the standard U50 on rubber strap. On a bracelet the price goes up to $2,260 and $2,360 with black hardened bezel. Fully hardened “T” models range from $2,650 (on rubber) to $2,940 for the all black “S” model on bracelet. This places the U50 in unique territory. Modern dive watch standouts like the Pelagos and Seamaster 300M are each well above this price point, thanks to their offering in-house movements and more exotic case materials. On the other end, options from the likes of Monta, Doxa and Mido can be had for under $2,000, but don’t quite hit all the same notes as the U50. 

The Oris Aquis

One option that does well against the U50 (on paper, at least) is the Oris Aquis Date. Oris uses their contemporary design language which is more subtle than the Sinn, though not entirely deferential to classic dive watch stylings. The Aquis measures in at 41.5mm, uses a Sellita SW200 and is priced at $2,200. While similar in stature, it’s difficult to imagine these being cross shopped, as the Oris will feature more polished surfaces and an overall more restrained look, offering a more luxurious take on the dive watch.


Another dive watch that has carved out a style all its own is the newly released Doxa Sub 300. You could classify these as throwback watches, because they are, but it’s a look made famous by Doxa and they’ve stuck with it. Plus, they now come packing a COSC certified ETA 2824, a step up from the Sellita in the U50. These watches are priced just under $2,500, but if cushion cases and beads of rice bracelets are what you’re looking for, the Sinn may never have been on your radar to begin with. These are awesome watches in their own right, but are a far cry from the sensibilities outlined by the U50. They do however offer a slimmer and very wearable cushion case and plenty of personality thanks to the 6 available colors.

The new DOXA Sub 300

From within Germany, we can find Nomos’ take on the dive watch in their Club Sport Neomatik. This is a capable diver that doesn’t adhere to any of the established dive watch lore, there’s no bezel, the seconds hand is relegated to a sub dial at 6 o’clock, and the entire case is polished. Priced around $4,000 it’s a bit out of reach from the Sinn regardless. Elsewhere in Germany is Damasko, who offer their own modern take on the dive watch in their DSub family. These are all around a fair bit larger than the U50 however, and offer no bracelet option. 

If you’re in the market for a U50, what else are you looking at? Let us know in the comments what we’ve missed.


Sinn has done something remarkable with the U50. It’s clear they’ve listened to the community of enthusiasts that feel underserved by mainstream brands producing either too large, too expensive, or too derivative options in their dive watch lines. This type of watch, at this price point, should find itself surrounded by viable options. But it’s not. Forget the price point, the U50 has garnered demand without reliance on a heritage design (I’m not counting 2005 as heritage), no artificial aging, and by placing a premium on the right dimensions. 

Works on NATO, too

Setting aside what I hope the success of the U50 means for the future of accessible dive watches, Sinn has produced a capable, everyday usable diver that’s available now. It’s not without fault, but there’s a lot to appreciate here and whether you’re a dive watch aficionado or looking for your first tool watch, the Sinn U50 deserves your attention. We’d recommend doing so sooner rather than later, as a price increase is imminent, and the order books aren’t getting any smaller.

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Blake is a Wisconsin native who’s spent his professional life covering the people, products, and brands that make the watch world a little more interesting. Blake enjoys the practical elements that watches bring to everyday life, from modern Seiko to vintage Rolex. He is an avid writer and photographer with a penchant for cars, non-fiction literature, and home-built mechanical keyboards.