Sinn U-Series Diver U1

The case measures 44mm across, with a 20mm lug width. Case material: German submarine steel (often tegimented/hardened). Case size alone is a poor guide to how a watch wears; lug-to-lug length and how the bracelet drops off the case matter more, which is why we suggest trying one on before you commit.

Automatic, Sellita SW200-1 (modified). Power reserve is 38 hours. It beats at 28,800 vph. The movement uses 26 jewels.

It is rated to 1000 meters, about 3281 feet. That is a diving rating: it is built for scuba use, not just for getting wet. One caution that applies to every watch on this page: a water resistance figure describes a new watch with fresh gaskets. On a piece that is years past its last service, treat the rating as unknown until it has been pressure tested.

Sinn produced this reference from 2005 to the present day. Production years matter when you are valuing one, because dial, bezel and bracelet details often changed inside a single reference run.

U1 = first U-series diver; case made from German submarine steel, often tegimented (surface-hardened). Reading the reference is the fastest way to confirm that a watch is what the seller says it is, before you get anywhere near the movement.

Sinn U1 (German submarine steel diver). Collector nicknames are not official Sinn names, but they are what people actually search for and what they are called across a showroom.

Yes. We buy this reference outright, and we lend against it if you would rather keep it. We are a family-owned San Diego buyer established in 2006, our appraisers are GIA-trained, and the appraisal is complimentary with no obligation to sell. You can bring it to our Gaslamp showroom at 907 Sixth Ave or start online. If you are looking to buy this reference instead, tell us and we will let you know when one comes in.