Watch The Navigation Chronograph 903 St II

The Watch

Founded in 1961, Sinn is a leading engineering-driven watchmaker with a wide range of technological innovations. The brand is known as the first to offer dive watches certified to European diving instrument standards. Today, this German manufacturer presents The Navigation Chronograph 903 St II. This pilot's watch features a 316L stainless steel case with a round shape, combining polished and satin finishes, with a diameter of 41 mm, a thickness of 14.5 mm, and a weight of 84 g. It is complemented by a bidirectional bezel with a logarithmic slide rule scale, adding both functionality and visual appeal. The case is topped with a double anti-reflective sapphire crystal for optimal dial legibility. On the right side of the case, a knurled and screwed crown in silver tone sits at 3 o'clock, flanked by two pushers at 2 and 4 o'clock. The caseback features a screwed and transparent display back fitted with an internally treated sapphire crystal, delivering 20 ATM water resistance. This edition is also compliant with the technical requirements of DIN 8310 (water resistance) and features low-pressure resistance.

The Dial

This watch boasts a striking black dial that elevates any look with understated elegance. It is enhanced by three sunray sub-dials delivering a stunning visual effect. A Tricompax chronograph, it features three identical sub-dials displaying 30 minutes at 3 o'clock, 12 hours at 6 o'clock, and small seconds at 9 o'clock. Hour markers consist of baton indexes paired with a single Arabic numeral at 12 o'clock. The hour and minute hands are styled in beige with a luminescent coating, while the central chronograph seconds hand is white with a red tip. A date window sits at an oblique angle at 4:30. Around the dial, 3 graduated scales complement the outer bezel to enable a wide range of aeronautical calculations.

The Movement

This model runs on a Swiss-origin automatic movement - the proven La Joux-Perret L110 caliber, featuring 26 jewels, a stop-seconds function, and a frequency of 28,800 vph (4 Hz). It delivers a 60-hour power reserve and offers magnetic field protection per DIN 8309. This movement provides reliable analog display and drives all additional functions at the highest level of performance.

The Strap

This timepiece comes with two straps selectable via the drop-down menu. Both straps feature a 22 mm lug width, branded by the manufacturer.

The first strap is crafted in brown calfskin leather with red contrast stitching. Elegant and comfortable, it fastens with a 316L stainless steel ardillon buckle and pairs effortlessly with any style for a truly unique look.

The second strap is crafted in satin and polished stainless steel for a distinctive look. Its brushed and satin-finished links add an authentic touch to the overall design. It fastens with a deployant clasp for effortless adjustment.

Water Resistance

With a water resistance of 20 atmospheres (200 meters), this model can confidently be called a dive watch. Our watchmaking experts agree: while it handles showers, baths, lap swimming, free diving, and recreational scuba diving with ease, it is not built for extreme deep-sea diving where pressure would exceed its limits. For professional divers chasing serious depths, we recommend models rated at 30 atmospheres or more. Also, avoid operating the pushers or crown while submerged to maintain a perfect seal.