A Long Overdue Encounter With The Impressive Sinn U50 Dive Watch

Sinn has no shortage of great watches. That became clear again last weekend at the brand’s stand at the WatchTime show in Düsseldorf, Germany. The big news was the new limited-edition 140 A S Anniversary chronograph, and it was a pleasure to try it on. Yet it was far from the only highlight. I was especially drawn to the extensive lineup of U-series dive watches, home to the U50, a model I have long admired, along with plenty of other cool options. Few brands offer such a wide range of capable, characterful tool watches. I also spent an extended period with the U50 to find out whether it can dethrone my favorite Sinn, the T50 in titanium and Goldbronze.

Sinn turns 65 this year and marked this milestone by releasing the 140 A S Anniversary that Nacho reviewed. Throughout its history, the brand has focused on building the best tool watches, and many fans admire it for exactly that. The utilitarian approach has paid off for the Frankfurt-based brand. Over time, that functional focus also shaped a strong visual identity, particularly for the U-series dive watches. They pair impressive specs with a distinctive look, making the line a fan favorite.

The details of the Sinn U50

Sinn introduced the U50 in 2020 as the U1’s smaller sibling. It trims the case from 44 to 41 mm wide and is considerably slimmer too. While the U1 is a hefty 14.7 mm thick, the U50 measures 11.15 mm. It’s also much shorter; instead of 51 mm long, it measures just 47.

The differences in diameter, thickness, and length make the U50 much more wearable. Back in 2022, Thor called it “an indestructible everyday tank of a watch.” The word “everyday” adds the nuance that makes this utilitarian dive watch such a good daily wearer.

The Sinn T50 followed in 2023, but it was not simply a titanium U50. The main changes were the switch from submarine steel to titanium and a slightly thicker 12.3mm profile. Sinn also fitted the T50 GDBR with a Goldbronze 125 bezel, and I adore that version. It gives the watch a look all its own.

Comparing the Sinn U50 to the T50

Beyond the case, the two models differ in several ways. The T50 has a safety bezel that you must push down to turn. The dials differ too. While the U50 has the signature U-series blocky markers and hands, single-tone lume, and bright red accents, the T50 has a more monochromatic white-and-gray dial with sword-style hands. Its white lume also glows in two colors to make nighttime diving easier.

Both series house the automatic Sellita SW300-1, which runs at 28,800 vph and offers a 56-hour power reserve. It is a reliable choice for both and allowed the designers to keep the cases significantly thinner than the U1’s while retaining the 500m depth rating.

The different Sinn U50 models

Sinn offers several U50 versions. The standard models come in steel (U50), steel with a black bezel (U50 SDR), and all black (U50 S). The U50 is also available with Tegiment, a patented surface-hardening technology that improves scratch resistance.

The oil-filled U50 Hydro models deliver reflection-free underwater readability from any angle and complete freedom from fogging. There have also been limited editions with special dials, including a mother-of-pearl version Lex reviewed and a blacked-out U50 with a dark blue gradient dial that Mike checked out. A few others show off the versatility of this series.

The standard stainless steel U50 landed on my desk for this review. As the meat and potatoes of the series, it’s the model most fans picture when discussing the U50. What stands out immediately is the color combination, which looks more serious than the T50’s.

The steel case gives the watch real heft and makes it feel like a professional dive watch that can take a beating. A new feature for the steel bracelet is a toolless micro-adjustment system, a welcome addition to the clasp, especially on a dive watch. It is very easy to use — just push a button inside the clasp to extend the bracelet.

Wearing the Sinn U50

Interestingly, the T50 shares the U50’s core specs, yet the two have different characters. The T50 comes across as more refined and stylish, especially with the Goldbronze bezel, which gives the watch plenty of attitude. Sinn introduced Goldbronze 125 for its corrosion resistance, though. No detail on these dive watches is there for aesthetics; everything stems from practicality and function. The U50 embodies that philosophy best, with a competent, sturdy build.

I have gone on record in my articles as favoring stainless steel over titanium, and I stand by that. But while I generally like steel’s heft more, I sometimes prefer titanium. On dive watches, it is a lightweight option that often looks good too. I love titanium’s slightly darker tone, especially when paired with a strong dial or a brighter, contrasting bezel, as on the T50 GDBR.

Final thoughts on the Sinn U50

The U50 pleasantly surprised me, partly thanks to the case’s nice heft. I also ended up loving the dial design. It has the signature U-series style, yet it is bolder and more characterful than the T50’s dial.

Before this review, I would have named the T50 as my favorite Sinn without hesitation. After a few days with the U50, though, I started going back and forth between the two. Seeing both series at the WatchTime show confirmed that each has a distinct charm and presence.

That brings the comforting thought that I don’t have to pick a winner. The two series look very different, and I love that. Each will eventually win people over. The U50 is the more hardcore, no-nonsense dive watch, whereas the T50 adds refinement and style.

Ask me for my favorite on different days, and the answer will change with my mood. Price complicates the choice further. The Sinn U50 costs €2,800 with the micro-adjustable bracelet, saving you over €1,000 compared with the T50, which sells for €4,200 on a bracelet (and €40 more than that on my preferred silicone strap).

Still, I’d credit that dilemma to the strength of Sinn’s lineup rather than to doubt. Six years after its debut, the U50 series finally won me over. All it took was wearing the basic stainless steel model for a few days. Sometimes, going back to the beginning is all you need to be convinced, and the Sinn U50 finally showed me just that.

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