Sinn UX (EZM 2B) Hydro Case Series
Dive Watch / Mission Timer (Einsatzzeitmesser) · Sinn Spezialuhren GmbH; independent German manufacturer. Known for technical innovation and professional-grade over-engineered tool watches.
Period: Modern Tool Watch (2000s-present); characterized by functionalist German engineering and utilitarian aesthetics.
Type
Dive Watch / Mission Timer (Einsatzzeitmesser)
Brand
Sinn Spezialuhren GmbH; independent German manufacturer. Known for technical innovation and professional-grade over-engineered tool watches.
Movement
High-accuracy quartz; ETA 955.652 Thermoline. Thermocompensated, 7 jewels, EOL (end of life) indicator, approximately 7-year battery life.
Dimensions
44mm diameter, 13.3mm thickness, 50.5mm lug-to-lug, 22mm lug width. Wears smaller due to the short, curved lugs.
Description
The Sinn UX is the ultimate professional diving chronometer. Utilizing a liquid-filled case, the watch is essentially incompressible, allowing it to withstand extreme depths while remaining perfectly legible from any angle underwater without the mirroring effect found in traditional watches.
Key Features
HYDRO technology (oil-filled case), German Submarine Steel construction, Tegiment surface hardening, high-accuracy thermocompensated quartz movement, 4 o'clock crown position.
Dial Description
Matte black dial with Sinn logo and 'UX' branding. Features 'HYDRO' technology (silicon oil filling) which eliminates reflection underwater. Highly luminous white indices and syringe-style hands with red accents (visible near center).
Case Material
High-strength German Submarine Steel (U-Boot-Stahl); salt-water resistant, non-magnetic. Features Tegiment technology coating for scratch resistance and a matte bead-blasted finish.
Crystal Type
Flat sapphire crystal with anti-reflective coating on both sides. The 'Hydro' oil filling makes the crystal virtually disappear under water.
Bezel Details
Unidirectional captive safety bezel; German submarine steel with Tegiment surface hardening. 60-minute scale with blue/cyan minute markers and a luminous triangle at 12.
Crown & Pushers
Screw-down crown located at the 4 o'clock position to prevent pressure on the back of the hand. D3-System for sealing.
Bracelet or Strap
H-link stainless steel (submarine steel) bracelet with a bead-blasted finish and a safety folding clasp with diver's extension.
Caseback Details
Solid screw-down caseback in German submarine steel with deep engravings including the Sinn logo, 'Hydro', and 'U-Boot-Stahl'. Allows for battery changes and oil refills.
Movement Type
High-accuracy quartz; ETA 955.652 Thermoline. Thermocompensated, 7 jewels, EOL (end of life) indicator, approximately 7-year battery life.
Water Resistance
5,000 meters (500 bar) for the movement; 12,000 meters (1,200 bar) for the case. Fully functional for saturation diving.
Origin & Provenance
Made in Germany (Frankfurt am Main). Case manufactured by SUG (Sächsische Uhrentechnologie GmbH) in Glashütte. Movement is Swiss-sourced.
Age Estimate
Modern production, likely circa 2010 to present based on the 'UX' dial markings and blue bezel accents.
Cultural Significance
Represents the pinnacle of 'over-built' horology. It is respected among collectors for choosing function over form and pushing the boundaries of physical durability in watchmaking.
Condition Notes
Very Good. Visible superficial scratches on the AR coating of the sapphire (common for Sinn). No visible air bubbles in the oil, which can sometimes occur in older units.
Value Estimate
$2,200 – $2,800 USD new; $1,600 – $2,100 USD pre-owned depending on Tegiment options and service history.
Care & Maintenance
Battery changes and oil service must be performed by Sinn in Germany or an authorized service center like RGM in the US due to the specialized oil-filling equipment required.
Similar Watches
Sinn U1 (Mechanical), Bell & Ross Hydromax (similar oil-filled tech), Breitling Avenger Seawolf (extreme depth rating), Resco Instruments RTAC.
Interesting Facts
The watch is official equipment for the GSG 9 (German Federal Police maritime unit). Because it is oil-filled, it is depth-rated for 5,000 meters for the movement and 12,000 meters for the case.