Sinn Revive 70s Design with Updated 903 St Navigation Chronograph Series

When it comes to navigation chronographs, there is one watch that dominates this particular niche of watchmaking. I’m of course talking about the Breitling Navitimer, the quintessential pilot’s chronograph with a slide rule bezel. However, Breitling by no means have a monopoly on this type of chrono as during the 70s Sinn acquired the rights to the design (but not the name) of the Navitimer from Breitling. The result is the 903, which Sinn have now revamped and revitalised with the new 903 St Navigation Chronograph series.

First of all, what is a navigation chronograph? Well, the origins take us back to the early days of aviation before aircraft were equipped with high tech instruments and pilots had to rely on traditional visual navigation. Visual navigation uses Instructions such as head north for 20 minutes then when you reach the lighthouse head west for 10 minutes – although typically in more official pilot lingo. Timing the intervals between each landmark is vital to make sure you are on course, which is why having a chronograph is extremely useful.

Additionally, a slide rule bezel that features a logarithmic scale can be used to calculate a number of equations. Particularly useful to pilots are speed, time and fuel consumption, all of which helps to ensure you are on track with your journey. Which all brings us to the Sinn 903 St and its revamped design.

There are three references in the updated series: 903 St II with a black sunray brushed dial, 903 St B E II with a blue dial and the 903 St HB limited edition with light blue sunray brushed dial. Certainly not the catchiest names but they are very cool watches nonetheless. They all measure 41mm in diameter with updated 200m water resistance ratings.

The other key updates include the hands and hour markers which are now made from hybrid ceramic and lume, making them solid block of luminous material. It’s even brighter and easier to see in low light conditions than traditional lume. Matching the style of the applied hour markers is the Sinn logo, which is also an appliqué.

Powering the watch is the La Joux-Perret LJP 110 column wheel chronograph with automatic winding and 60-hour power reserve (the limited edition houses the LJP 112, which is the same sans date function). A highly reputable off the shelf movement.

All that remains to discuss is the price and both standard versions of the 903 St Navigation Chronograph, the II and B E II, are €3,250 on leather or silicone strap and €3,550 on steel bracelet (approx. £2,790/£3,050). The limited edition HB is €3,650 and comes with both a leather strap and steel bracelet (approx. £3,130).

More details at Sinn.