With this updated example of De Bethune’s only sports watch, the DB28GS, the innovative watchmaker places its technical stamp on the light-up dial.
To illuminate the watch and the movement from the inside, De Bethune has created an unusual mechanically powered blue-white light. Requiring no battery, the light briefly illuminates the watch in a manner similar to the dynamo-based method found on many bicycles. A pusher at 6 o'clock activates a small gear train driven by the twin barrel. This gear train, by means of a miniature dynamo, provides the necessary energy for the light. Should the watch’s five-day power reserve drop below one day the light function will be blocked to save energy.
That’s not all De Bethune does to expand the idea of a traditional sport watch. In place of a standard rotating unidirectional bezel found on traditional dive watches, De Bethune moves the dive-time markers from the bezel to the sapphire crystal itself, creating a less busy bezel and a thinner-than-usual diver.
The new caliber inside, which is De Bethune’s twenty-seventh, is hand-wound with central seconds and a five-day power reserve indicated on the dial. It’s equipped with an in-house-made balance wheel made of titanium and white gold. In true De Bethune fashion, the movement is fully thermo-compensating, anti-magnetic and is shock resistant thanks to a triple pare chute system with two shock absorbers astride, and one directly on, the balance wheel.
De Bethune has also redesigned the lugs for the 44mm titanium watch and added black zirconium inserts to the lug’s cones to match the sides of the case. The watch is delivered with two straps: a canvas version and a striated natural rubber iteration with titanium folding clasp. Only thirty pieces will be made annually.
Specifications: De Bethune DB28GS Grand Bleu
Movement: DB2080 hand-wound, winding and setting the time by means of the crown (2 positions), push button at 6 o’clock to activate the light, 5 days power reserve ensured by a self-regulating twin barrel, titanium/white gold balance wheel with white gold inserts, optimized for temperature differences and air penetration (De Bethune Patent 2016), "De Bethune" balance-spring with flat terminal curve (De Bethune Patent 2006), silicon escape wheel, Triple pare-chute shock-absorbing system, dial lighting produced by entirely mechanical means, mirror-polished grade 5 titanium motion-work bridge plate and barrel, bridge covers in hand-smoothed grade 5 titanium and adorned with “Microlight engraving”
Display: Functions: Hours, Minutes, Seconds, Power reserve indication between 9 and 10 o’clock, unidirectional rotating bezel, manual dial lighting
Case: 44mm by 12.8mm black zirconium case, middle with “Microlight” decoration, brushed and polished grade 5 titanium caseback and bezel, floating lugs in brushed grade 5 titanium
Dial: Blued titanium hours and minutes hands with polished steel insert and second blued steel insert, luminescent tip, polished steel seconds hand with luminescent tip, power-reserve indicator between 9 and 10 o’clock, satin-brushed grade 5 titanium minutes dial with cut-out Arabic numerals, rotating bezel crystal with metallized minutes ring
Strap: Natural rubber plus 1 canvas / leather strap, folding clasp in brushed grade 5 titanium