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When it comes to functional innovation, few can hold a candle to the Frankfurt watchmaker Sinn. Known primarily for its pilot's watches, the brand has another specialty in its uncompromising dive watches, relying on a host of unique technologies underwater. From submarine steel to TEGIMENT to Ar-Dehumidifying Technology: we explain what sets this traditional German brand apart and which diver is the right one for you.
Developed by ThyssenKrupp: Genuine Submarine Steel
Whether it's the golden gleam of a wafer-thin gold plating or a supposed in-house movement with ETA roots: look more closely at the watch world, and some things turn out to contradict their first impression, often leading to disappointment. With the Sinn U collection, it's pretty much the other way around, because here your enthusiasm grows the deeper you look. At first glance, the cases of these dive watches seem to be made of ordinary stainless steel, but in reality the material is a special development by ThyssenKrupp, created for the German Navy's Class 212 submarines.
Anything used in the world's most advanced non-nuclear submarines has to deliver: not only its strength rating of 155% compared with conventional 316L stainless steel, but also its antimagnetic properties and high resistance to salt water set the material apart from that of other divers. Completely resistant to prolonged contact with seawater, Sinn U models don't even need to be rinsed after use, and they also offer greater resistance to cracking than conventional grades of steel. There is no difference in quality within the U editions; the cases of all divers from the city on the Main are made exclusively of this military-grade material.
Certified to European Diving Equipment Standards
Robustness on this level deserves proper confirmation. That's why Sinn doesn't send its dive watches to just any lab to test water resistance and pressure resistance, but to DNV GL (formerly Germanischer Lloyd) in Hamburg. Where breathing apparatus and other diving equipment are normally tested for their fitness for use, a dedicated test procedure for Sinn's timepieces was established in 2005, putting the divers through an almost agonizing ordeal – three hours at minus 30° C and another three hours at 70° C and 95% humidity are mandatory.
In terms of maximum diving depth, Sinn U watches can be divided into four categories: 500 meters (50 bar), 1,000 meters (100 bar), 2,000 meters (200 bar) and – no joke – unlimited diving depth in the case of the UX series. Its case withstands an incredible 12,000 meters, exceeding the deepest point of the world's oceans in the Mariana Trench by several hundred meters.
Five Models, Five Requirements: Our Sinn U Favorites
But it doesn't take 1,200 bar to create a really good diver. The U50 series proves it: its 500 meters of water resistance may sound a bit modest next to the four-digit figures of its sister models, but by Swiss standards it definitely belongs in the high-end league. Just for comparison: the Omega Seamaster 300 - an established giant in this class - manages "only" 300 meters.
A major advantage of the U50 over its more rugged relatives is its wearable 41-millimeter case size, paired with the brand's own TEGIMENT Technology and - as with all U models - a crown offset to 4 o'clock.
While TEGIMENT refers to a special process for hardening the surface of the case, delivering extreme scratch resistance, the unusual crown position keeps it from digging into the back of your hand. So that's two innovations in one go, but the Frankfurt manufacturer's repertoire has even more to offer.
Take the U 212 series, for example: water-resistant to 1,000 meters and measuring 44 millimeters, it surpasses the U50 in two respects at once and falls into the category of so-called "mission timers" (EZM) from the brand founded in 1961. But its second name, EZM 16, shouldn't distract from the fact that the U 212 is an uncompromising maritime giant. In the style of all its Sinn U sister models, it features a captive rotating bezel with minute-by-minute ratcheting and also offers Ar-Dehumidifying Technology. Like TEGIMENT, this is one of the brand's own developments, comprising a whole package of measures to keep the movement completely dry.
Drying capsule, protective gas filling, diffusion-reducing EDR seals - Sinn picks up where the dive watches of many luxury brands stopped long ago. By the way: if you want to experience the size and functionality of the U 212 at a lower price without Ar-Dehumidifying Technology, the 44-millimeter U1 collection is a good alternative - 100 bar pressure resistance included.
Size and Depth: The Superlatives
If, on the other hand, you want something more extreme, the U2 is the watch of choice. Three features set it apart from its "little brother," the U1: first, twice the diving depth at 2,000 meters; second, a case enlarged to a monumental 47 millimeters; and third, a GMT function. Incorporating all the innovations mentioned so far, it takes the professional capability of the mechanical Sinn U models to the maximum and is surpassed in diving depth only by the UX. By a wide margin.
But it's not just the 12,000 meters of water depth that make this 44-millimeter diver exceptional - it's also its HYDRO Technology: behind it lies - who would have guessed - yet another Sinn technology, whose special anti-reflective treatment ensures perfect legibility underwater from any angle. For lovers of mechanical watches, however, the UX is hardly an option: powered by a thermocompensated quartz movement, it differs fundamentally from the mechanical Sellita and ETA calibers of all the editions mentioned so far. The reason: no automatic movement could withstand the incredible pressure at the bottom of the Mariana Trench.
A Highlight in Its Own Right: Value for Money
Our journey through the world of Sinn dive watches with a U is drawing to a close, but it makes no claim to be complete: the full product portfolio of the Frankfurt divers extends well beyond these five models. Their special features – from the offset crown to HYDRO Technology – nonetheless represent the German company's unique innovative strength in making professional divers.
But we haven't yet mentioned one of their greatest strengths - their value for money: all the editions presented here range between €1,500 and €3,000. If you can do without the prestige of an Omega and its in-house movements, you get an unparalleled combination of quality, technology and performance in return.
