Sinn · Family: U1
The Sinn U1 is Sinn's flagship dive watch, cased in 44mm of German submarine steel and rated to 1,000 meters of water resistance. It runs an automatic movement built on the Sellita SW200-1 base. Cazador has no verified price observations as of July 2026. Its differential: Ar-Dehumidifying Technology, which injects dehydrated argon into the case to prevent internal crystal fogging — a proprietary feature rare among dive watches.
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Sinn Spezialuhren was founded in 1961 in Frankfurt am Main by test pilot and flight instructor Helmut Sinn, which explains the aviation roots running through much of the brand's catalog. The U1, introduced as part of the EZM ('Einsatzzeitmesser,' or mission timer) series of tool watches built for emergency-response units and professional diving, represents the most rugged end of that philosophy.
The construction detail that gives the reference its popular identity is the case: Sinn machines it from a special German submarine steel, a material originally developed for German submarine hulls, chosen for its resistance to marine corrosion and its non-magnetic behavior. The 44mm case also undergoes Sinn's Tegiment surface-hardening treatment on the bezel, improving scratch resistance without altering the steel's matte finish.
Under the dial sits an automatic movement built on the Sellita SW200-1 base, a Swiss-made third-party caliber widely used across the industry for its reliability and parts availability, delivering roughly 38 hours of power reserve.
The stated 1,000-meter water resistance places the U1 far beyond the 200-300m standard typical of sport dive watches, a margin Sinn attributes to the EZM series' over-engineering philosophy. Layered on top of that is Ar-Dehumidifying Technology, a proprietary system that fills the case with a dehydrated argon atmosphere to minimize internal crystal fogging under sudden temperature swings.
No verified launch year is available in the manufacturer catalog data used for this fiche. What is confirmed is that the U1 remains in Sinn's current lineup and in active production.
Cazador has no verified price observations for the U1 yet, so we do not publish a market range. This section activates once sufficient data exists.
It's a special steel originally developed for German submarine hulls, used by Sinn in the U1's case for its resistance to marine corrosion and its non-magnetic behavior.
It runs an automatic movement built on the Sellita SW200-1 base, one of the most widely used Swiss third-party calibers, with roughly 38 hours of power reserve.
Sinn rates the U1 to 1,000 meters of water resistance, far beyond the 200-300m standard typical of sport dive watches.
It's a proprietary system that fills the U1's case with dehydrated argon to reduce internal crystal fogging under sudden temperature changes.
It's a surface-hardening treatment Sinn applies to the steel bezel to improve scratch resistance, without changing its matte finish.
Yes. Per the manufacturer's current catalog data, the U1 remains in active production today.