Monochrome Watches
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Sinn U50, The Smaller Version of The U1 Diving Instrument (Live Pics & Pricing)

Reduced in size, still purpose-built, still essential.

| By Brice Goulard | 4 min read |
Sinn U50 German Submarine Steel Dive Watch - Smaller U1

If you’re into retro-looking, precious and trendy (desk) dive watches, the following watch isn’t for you. What’s coming below is modern, utilitarian, over-engineered and very German indeed. No surprises, it’s a new Sinn watch. Well known for its pilot’s chronographs, the brand also has a solid track record in diving instruments, one of the best examples being the U1, the “diving watch made of German Submarine Steel”. Although its efficiency no longer needs to be proved, this watch might be problematic for some, as it is really large. Problem solved, with the Sinn U50, basically a smaller version of the U1 with almost no compromises on the original concept.

Sinn U50 - U50S - U50SDR - Dive Watch
This new watch comes in three tastes: the Sinn U50 SDR (black bezel), U50 S (full black) and U50 (non-coated).

The reduced U1

One of the best examples of an engineered dive watch by Sinn – understand by that a watch that has been designed and developed with performance as its utmost purpose, and not to look good lounging by the pool – is the U1 model. Equipped with most of Sinn’s technologies – TEGIMENT coating, German steel case, captive diver’s bezel – and tested, certified and approved by most diving watch standards (ISO and DIN), it became appreciated by the diving community for this “purpose-built” spirit, resulting in a no-nonsense and highly utilitarian design.

Sinn Dive Watch U1 vs U50
The new U50 next to the classic U1. Same design, almost equally performing, sharing all technologies, just smaller.

The Sinn U1 is a proven tool, with 1,000-metre water-resistance and a fully protected case, which might be problematic for some since it measures 44mm in diameter and has a “rock solid” feeling. Sinn is solving this issue this year with a new watch that is basically a reduced U1. Smaller, more compact, thinner, sharing most of the design cues and specifications, almost as performant, its name is the U50.

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The Sinn U50 collection

The new Sinn U50 doesn’t come as a surprise for the brand’s enthusiasts, which will find all the signature elements of the previous, larger U1 model. In short, it’s just a matter of proportions here, and a few concessions on the performance, with a water-resistance that is now rated at 500m vs. 1,000m on the U1 – explained by the smaller case, but still more than enough, even for professional divers.

Sinn U50 German Submarine Steel Dive Watch - Smaller U1

The case of the Sinn U50 is now 41mm in diameter and relatively thin for such a tool watch, at 11.4mm. It is made of German Submarine Steel (Deutscher U-Boot Stahl), with a matte and very utilitarian bead-blasted finish – don’t expect it to look luxurious, it isn’t made for that anyway. Sapphire crystal, screw-down crown and screwed caseback come as standard, as well as a fully-graduated unidirectional bezel with diving scale. And when it comes to certifications and standards, the watch is pressure-certified by DNV GL, it meets the requirements of the diving norm DIN 8306, and European diving equipment standards EN 250 / EN14143.

The dial of the Sinn U50, its diameter and the size of the indexes excluded, is exactly identical to the bigger brother U1. Here again, no concessions to luxury or vintage, with functional hands and indexes, combining white luminescent paint and red accents. The dial is matte black to avoid reflections and all the elements make it extremely legible. It features a date at 3 o’clock, with a tone-on-tone disc. Inside the case is a tried-and-tested automatic movement, the Sellita SW300-1 (clone of ETA 2892) with 4Hz frequency and 42h power reserve.

The Sinn U50 also follows its bigger brother U1 when it comes to the versions available. Not one but three models have been launched. First is the classic U50, without coating. Then is the U50 SDR, which features a bezel with Black Hard Coating on a TEGIMENT Technology basis. Finally, there’s the U50 S, a full black model, once again with Black Hard Coating on a TEGIMENT Technology basis – TEGIMENT is a proprietary hardening technology, which creates a 1200-Vicker protective layer (“tegimentum” in Latin).

Sinn U50 German Submarine Steel Dive Watch

The Sinn U50, U50 SDR and U50 S all come standard on a black, red or white rubber straps with a folding clasp. A steel bracelet is also offered, with or without black coating to match the case material.

Price and availability

The three versions of the Sinn U50 dive watch can now be ordered on the brand’s website, with deliveries expected early June 2020. The prices start at EUR 2,160 for the U50, EUR 2,230 for the U50 SDR and EUR 2,600 for the U50 S.

More details at

5 responses

  1. That is the whole point of using submarine steel as it is much more corrosion resistant than standard stainless steels.

  2. Holy canoly!! That black U50S on rubber is almost the Sinn diver I always wanted. I say almost because date-less would be, imho, pure perfection, but I still want this. Any word on what modifications Sinn have made to the Sellita movement? That’s my only concern with Sinn, typically. Makes me a tad apprehensive getting them serviced at regular shops when the time comes.

  3. @Matti – regarding the movement, there are probably almost no modifications. This is the kind of movement that most capable watchmakers can service very easily.

  4. I would normally be negative about this watch simply because it’s a dive watch.
    I’m very surprised there’s no garish bright colour for the face or that it looks too bulky.
    I can’t fault this except for the date window,I want one it’s great looking better sized and with a range of straps, cracking tool watch

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