De Bethune launched this January an interesting piece – the DB28GS Grand Bleu. The name maybe is not suggestive enough but this watch is the first piece with diving characteristics: higher water resistance, rotating bezel, illuminated dial and bezel. Instead of using the now-classic SuperLuminova, De Bethune uses micro-led technology and mechanical generators to offer light-on-demand.
Review: De Bethune DB28GS Grand Bleu
De Bethune DB28GS Grand Bleu was launched during the days of SIHH 2019 (more precise on Sunday, January 13th) during a lovely event at Hotel Beau-Rivage*****). I have presented the first images and video with the watch that evening: here. I will add the initial video and images again in the gallery section.
De Bethune articulated lugs
The De Bethune DB28GS Grand Bleu comes with the brand’s specific articulated lugs. These not only look tremendous but bring increased comfort in wearing. The lugs permit a comfortable adaptation to the wrist size and to the wrist movements.
The case is manufactured in titanium and presents a matt finish due to its subtle brush. The skeletonised lugs received black zirconium insert. The lugs design is similar to the DB28 Kind of Gold and the DB28 Yellow Tones. The case complexity is fine accompanied by its sober finishes.
The crown is placed, as expected in the DB28 Collection, on the top of the watch, at 12 o’clock. Using the crown is a strange process for the ones not used to the system. I find easier just to remove the watch from the wrist to do the winding/set. Otherwise, the use of the crown is facile and fun.
On the other side of the case, at 6 o’clock it is placed the push-button for the light system. The large pusher is protected on both sides. By normal wear, the button is also kept safe by its unusual position.
Here stays the innovation of DB28GS Grand Bleu. By pushing this, an innovative system is lighting the dial and bezel. The system is fully mechanical, based on the dynamo principle. The system uses the energy to supply four micro light-emitting diodes (LED).
The watch is rated at a water resistance of 105m. The unusual ratings come from Luc Besson’ movie – Le Grand Bleu, where the main character dive as low as 105m. The name of the watch withdraws inspiration from the same film.
DB28GS Grand Bleu has a gorgeous dial, specific in style and construction to De Bethune. The watch face breaths pure De Bethune style. This time, the watch received a rotating bezel and notations specific to the diver watches. As an older design element, the Start Trek badge style bridge is still present on the dial.
The crystal received a black register with minute indexes that serves as a diving indication. Another inner bezel bears two tracks of indexes.
On the left side of the dial is present the power indicator for the five days power reserve and light system. In this picture is completely depleted. But on the light exemplification video, one can see the power reserve and the speed of depletion.
The Grand Bleu uses a large hour’s hand manufactured from thermally blued titanium with a polished steel insert and a SuperLuminova tip.
For minutes’ hand, De Bethune chose a slender blued titanium arrow with SuperLuminova tip. The seconds’ hand is manufactured even more slender but was not blued.
De Bethune DB28GS Grand Bleu is extremely well protected against mechanical shocks. Visible in the picture above is the triple pare chute system: the classical shock protection in the balance wheel axe received extra protection by adding shock protection to the bridge. I wonder if the brand tested the system and what was the final outcome.
The Grand Bleu received a new movement, the 27th De Bethune calibre. Most of the movement is visible on the dial side.
One of the key features is the titanium and white gold balance wheel and balance-spring with a flat terminal curve. Beating at 4Hz, the system ensures an ideal mass/inertia ratio for this frequency.
The movement is designed and finished in the typical De Bethune style. On the dial side, it offers an amazing show. On the backside is technical and hard comprehend. The photographed piece is a prototype and maybe the series pieces will receive a detailed finishing on the back.
Hands-on and lighting example videos
A short hands-on from the official launch event:
But most of us have long waited to see the micro led light in action:
A step further – conclusion and personal impressions
The diving watch purists and the avid divers might not consider the De Bethune DB28GS Grand Bleu a “real” diving watch. But I am sure that De Bethune does not intend to replace the traditional diving computers and analogue, well-established diver watches. What the independent brand does it to reinvent the wheel. More precise the use of it. De Bethune is one of the pioneers: always new technologies, always pushing the limits, always reinventing.
The idea of using “old” technologies with a new implementation and purpose is the real trick and innovation. DB28GS Grand Bleu explores new territories.
As a De Bethune fan, I was amazed by DB28GS Grand Bleu. Like any other De Bethune piece, it looks and feels great on the wrist. Playing with it, it reveals the same fabulous construction and exceptional finishes without revealing the gimmick. In fact, you have no hint what the DB28GS is hiding – or better said, what is revealing.
My possible biased opinion does not exclude the remarkable achievement.
De Bethune DB28GS Grand Bleu Technical specifications
Functions: Hours, Minutes, Seconds, Power reserve indication between 9 and 10 o’clock, unidirectional rotating bezel, manual dial lighting
Type: Mechanical hand-wound movement
Adjustment: Winding and setting the time by means of the crown (2 positions), push-button at 6 o’clock to activate the lightening
Technical features of calibre DB2080
Number of parts: 400
Jewelling: 51 jewels
Diameter: 30 mm
Power reserve: 5 days, ensured by a self-regulating twin barrel De Bethune Innovation (2004)
Frequency: 28,800 vibrations per hour
- Titanium/white gold balance wheel with white gold inserts, optimised 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 – De Bethune Innovation (2005)
- Dial lighting produced by an entirely mechanical means working on the dynamo principle powered by a twin-barrel and manually controlled via a pusher – De Bethune Innovation (2019)
- Mirror- polished grade 5 titanium motion-work bridge
- Plate and barrel bridge covers in hand-smoothed grade 5 titanium and adorned with “Microlight engraving” – De Bethune Innovation (2007)
- Hand-snailed barrels
- Hand-polished and chamfered steel parts
- 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 metallised minutes ring
Case and strap
Case material: Black zirconium case middle with “Microlight” decoration, brushed and polished grade 5 titanium caseback and bezel
Case diameter: 44 mm
Case thickness: 12.8 mm
Lugs: Floating lugs in brushed grade 5 titanium – De Bethune Patent (2006)
Crystal: In sapphire crystal (1800 Vickers hardness) with double anti-reflective coating
Case back: open in brushed grade 5 titanium
Water resistance: 10 ATM
Strap: Natural rubber strap + 1 canvas / leather strap
Buckle: Folding clasp in brushed grade 5 titanium