Ulysse Nardin Diver [AIR]: the world’s lightest mechanical dive watch

Ulysse Nardin presented the Diver [AIR], the world’s lightest mechanical dive watch. In titanium and carbon, ref.3743-170-2A/0A is priced at CHF36,000

To achieve the Diver [AIR]’s remarkably light weight of just 52 grams, strap included, Ulysse Nardin developed a cutting-edge movement, the 3 Hz (21,600 vibrations per hour) calibre UN-374, which had to be completely reimagined and redesigned from the ground up.

This was done without compromising reliability or performance. Ulysse Nardin’s designers removed material from the movement while somehow making it stronger. As mass was reduced, the remaining components were cleverly repositioned to increase structural strength. 

The bridges, shaped into triangles, follow a design long used in engineering for its resistance to bending and deformation.

As a result, and despite the fact that 80 percent of the space inside the case is air and only 20 percent material, the skeletonised UN-374 calibre is capable of withstanding shocks of up to 5,000 g. The movement has also undergone rigorous testing against impacts and vibrations, not only in the lab but also in real-world conditions.

The bridges are barely a few millimetres wide, hollowed out to save even more weight, while the winding rotor has been reduced to the essentials.

The mainspring barrel, where the power is stored, has been reconfigured into a flying arrangement to reduce the mass of the top bridge. Even the barrel itself has been pared down to reduce weight further, bringing the total weight of the calibre to just 7 grams.

Still, the automatic calibre UN-374 offers an impressive 90-hour power reserve.

The material of choice is titanium, marking a bold departure from tradition. Brass offers strength and ease of machining but is relatively heavy. Aluminium is much lighter, yet lacks the durability required for high-precision components. 

Titanium, by contrast, delivers an outstanding strength-to-weight ratio, though it is difficult to machine and poses a fire risk during production. These factors explain its rarity in movement construction.

Ulysse Nardin embraced this technical challenge, employing titanium in the Diver [AIR] for the first time. The movement is further enhanced by a lightweight, antimagnetic silicon escapement that weighs half as much as a conventional one, ensuring precision timekeeping while keeping mass to a minimum.

For the 44 mm × 14.7 mm case, Ulysse Nardin chose a modular construction combining titanium and carbon fibre.

The movement is encased in a titanium middle case providing 200 metres / 660 feet of water resistance, with side parts in carbon fibre. This material is not only visually appealing but also boasts an exceptionally low density of just 1.8 g/cm³, less than a quarter that of steel and half that of titanium.

The luminous bezel insert is forged from CarbonFoil, made of 100 percent upcycled carbon fibres from IMOCA boats, chopped and compressed into a marble-like pattern.

The watch is delivered with two interchangeable ultralight and elasticated straps in white and orange, fastened with a Velcro closure for added practicality.

The Ulysse Nardin Diver [AIR], ref. 3743-170-2A/0A, is priced at CHF 36,000. 

ulysse-nardin.com

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