Sinn‘s trademark line of dive watches all have cases made of a corrosion resistant steel alloy used for German navy submarines. Just introduced at Baselworld 2015, the latest model in this line-up is the U212 S E, featuring the largest case Sinn makes for its dive watches at 47 mm in diameter.

Surface hardened with Sinn’s proprietary Tegiment process, the submarine steel case is also PVD coated with a black ceramic layer for exceptional scratch resistance.

As with many of Sinn’s other tool watches, the Sinn U212 S E is tested by DNV GL to industrial standards for diving equipment. DNV GL is a German testing and certification firm whose business includes setting safety standards for ships and oil rigs, meaning its 1000 m water resistance rating is independently verified and dependable.

The U212 S E is also equipped with Sinn’s Ar Dehumidifying technology. The case is filled with an inert argon gas to keep moisture out, and also fitted with a capsule containing copper sulphate powder, functioning as a dehumidifier by absorbing moisture from inside the case. This prevents fogging on the crystal, and also the minor rusting and corrosion that can happen when water vapour seeps into the case, due to old gaskets or improper screwing of the crown.

Matte black with ivory Super-Luminova for the vintage look that is fashionable today, the dial shows the copper sulphate capsule through a tiny window at six o’clock as well as the “Ar” logo at nine.

The Sinn U212 S E is a large watch, with a case diameter is 47 mm and a thickness of 14.5 mm. And it is also heavy, weighing some 135 g, or 4.7 oz, without the strap, in part due to the density of submarine steel.

The movement inside is the SW 300, the Sellita clone of the ETA 2892. Sellita is a low-cost movement supplier that makes copies of ETA calibres, since the patents have expired on the decades old ETA movements. It is automatic with a 48 hour power reserve.

Limited to 300 pieces with each individually numbered, the U212 S E will cost €2360 with a leather band (shown at bottom), and €2590 with a rubber strap fitted to a Tegiment treated and black coated diving clasp.