Hands-On: Ulysse Nardin Diver [Air] Watch

Shot on Leica by Jake Witkin and Ed Rhee

Humans naturally associate weight with quality, and it is therefore rather easy for us to be impressed by an extremely heavy timepiece. However, exceptionally lightweight watches can sometimes be even more impressive, as they appear to defy the laws of physics and create a cognitive dissonance between what your eyes see and the physical object that you experience in your hands. A perfect example of the latter variety of “impressive” is the Ulysse Nardin Diver [Air], which is a sizable 44mm dive watch with a proper 200-meter depth rating that somehow manages to weigh less than a tennis ball, even including its strap.

At a quick glance, the Ulysse Nardin Diver [Air] (ref. ref. 3743-170-2A/0A) almost looks like someone forgot to install the majority of the internal components inside one of the brand’s standard Diver X Skeleton watches. However, the Diver [Air] only resembles the Diver X Skeleton in its case shape and overall appearance, and virtually every aspect of both its case and movement has been re-engineered for maximum weight reduction. In our original news article about the Diver [Air], I wrote that the watch weighs just 52 grams with its strap, and this is a figure that Ulysse Nardin even references on its official website. That said, during our meeting with the brand this year at Watches & Wonders Geneva, I learned that the Diver [Air] actually weighs slightly less with a total weight of 51.51 grams (including its strap), or 46 grams for just the head of the watch itself.

Maybe Ulysse Nardin was just accounting for the additional weight of the strap when wet (it is a dive watch, after all), but if you examine the specifications for the Diver [Air] on the brand’s website, you will find a value of 51.51 grams listed as the model’s official weight. As a point of reference, a standard tennis ball weighs between 56 and 59.4 grams, and one of Ulysse Nardin’s traditional 44mm titanium Diver models has a total weight of 120.49 grams. Given that an entry-level DW5600 series Casio G-Shock also happens to weigh 52 grams, it’s not like the Ulysse Nardin Diver [Air] is putting up figures that simply don’t exist within the wristwatch industry; however, while we fully anticipate a resin G-Shock to be lightweight, the Diver [Air] completely defies expectations when you first pick up the watch and hold it in your hands.

Measuring 44mm in diameter by 14.7mm thick, the Ulysse Nardin Diver [Air] is a millimeter thinner than one of the brand’s Diver X Skeleton models, although it is still hardly a small timepiece, and the model’s fairly sizable proportions create certain expectations for what an object of this size should feel like in your hands. Cognitive dissonance begins to set in when you pick up the Diver [Air] and it weighs less than half of what you were expecting, and the experience provides a similar tactile thrill that someone might get from handling an inexplicably heavy watch. However, while it is rather easy to make a watch extremely heavy, you can only remove so much weight without compromising its structural integrity or functionality, and this is where the Diver [Air] really starts to become impressive.

Despite its ultra-lightweight construction, the Ulysse Nardin Diver [Air] makes zero compromises when it comes to durability, and the model is shock-resistant to 5,000g with a properly dive-capable 200 meters of water resistance. In order to achieve these performance metrics, Ulysse Nardin couldn’t just make the same components thinner and more skeletonized, as there simply isn’t enough material to remove from the Diver X Skeleton. Instead, the brand had to explore different materials for both the case and movement, and it collaborated with multiple different entities from the advanced materials industry to create special blends of titanium and carbon fiber, which also place a strong emphasis on recycling and sustainability.

Just as you would expect, the Ulysse Nardin Diver [Air] features two sapphire crystals fitted to either side of its case, with a domed crystal protecting its dial and a flat circular crystal fitted to its screw-on display caseback. However, this is more or less where the material similarities end. The central section of the Ulysse Nardin Diver [Air]’s case, along with its bezel ring, screw-down crown, and caseback frame are all crafted from 90% recycled titanium that has been produced through a collaboration between the companies TiFast and Thyssenkrupp. TiFast is one of Europe’s leading titanium producers, and it recovers the titanium used for the Diver [Air] from the Swiss biomedical industry. From there, the reclaimed metal gets handed over to Thyssenkrupp, which processes the titanium to further enhance the alloy’s deformation and machining properties.

Meanwhile, the rest of the Ulysse Nardin Diver [Air]’s case is constructed from a proprietary carbon-composite material known as Nylo®-Foil, which has been specifically engineered to be both sustainable and even lighter than traditional carbon fiber. To create Nylo®-Foil, carbon fiber is reclaimed from IMOCA sailing boats manufactured by CDK Technologies, and the carbon fibers are recycled back into their original fibrous state by Extracthive, which is a company that specializes in recycling carbon fiber from composite waste. Carbon fiber accounts for 40% of Nylo®-Foil’s composition, with the remaining 60% consisting of Nylo®, which is a Nylon 6-based polymer made by Fil & Fab using recycled fishing nets. The Nylo® and reclaimed carbon fibers are then given to Lavoisier Composites, and the French company processes the two materials to create the Nylo®-Foil used for the Diver [Air]’s outer case sections.

Even the luminous carbon-fiber bezel insert on the Ulysse Nardin Diver [Air] is stated to be different from what can be found on the various other models from the brand’s Diver collection, although the two carbon-based materials offer a near-identical overall appearance. Rather than being crafted from Carbonium like the inserts fitted to the brand’s other Diver models, the bezel insert on the Diver [Air] is made from CarbonFoil, which is made using 100% recycled carbon fiber that has been reclaimed from IMOCA sailing boats. The recycled carbon fiber is chopped up and compressed into a solid structure to form the lightweight CarbonFoil material, and the bezel insert is then machined to reveal a dense marble-like pattern of black and gray hues that is similar to the asymmetric wavy lines that characterize standard forged carbon.

Traditionally machined from brass, mechanical watch movements often account for a significant percentage of a timepiece’s overall weight. Therefore, in order to make the Diver [Air] as lightweight as possible, Ulysse Nardin needed to change both the design and materials of its self-winding movement. The plates and bridges of the Caliber UN-374 that powers the Diver [Air] are crafted from the same 90% recycled titanium that is used throughout the case, and the entire movement has been skeletonized to the absolute bare essentials, with its open-worked mainspring barrel even opting for a flying configuration to eliminate the need for an upper barrel bridge. In fact, approximately 80% of the space inside the Diver [Air]’s case is occupied by nothing but pure air, and this explains why the model almost has the appearance of being fitted with only part of an internal movement.

Running at a frequency of 21,600vph (3 Hz) with a power reserve of approximately 90 hours, the 21-jewel Caliber UN-374 consists of 199 individual components, and similar to other Ulysse Nardin manufacture movements, the Cal. UN-374 features the brand’s signature oversized balance wheel for superior accuracy and stability. To ensure that its ultra-minimalist skeletonized movement can still withstand forces up to 5,000g, Ulysse Nardin has engineered the brides of the Caliber UN-374 to create triangular shapes (the strongest geometric form), and its hairspring, anchor, and escape wheel are all crafted from silicon to further enhance the movement’s resistance to magnetism and temperature fluctuations. Even the silicon used by the Diver [Air] places an emphasis on sustainability, and the Cal. UN-374’s regulatory components are crafted from recycled silicon wafers that have been supplied by Sigatec.

To further lean into its lightweight construction, the Ulysse Nardin Diver [Air] is paired with an elastic fabric strap that uses a velcro-style fastening system, and both orange and white versions of the strap are included with the watch. Similar to the Sport Loop band popularized by the Apple Watch, the straps for the Diver [Air] mount to the 12 o’clock side of the case and wrap around the springbar on the opposite end before latching onto themselves with their velcro-style closures. However, unlike Apple’s Sport Loop that is entirely fixed at the 12 o’clock side, the straps for the Diver [Air] also use velcro to connect around the 12 o’clock springbar, and this approach allows owners to adjust the total length of the strap to center its velcro-style closure on the bottom of their wrist. Additionally, since velcro is used for both connection points, owners can easily swap between the two included options without the use of any tools or a proprietary connection system that would limit the range of compatible third-party straps.

Due to its highly skeletonized appearance, the one area where the Ulysse Nardin Diver [Air] doesn’t excel is when it comes to at-a-glance legibility, which is normally one of the hallmark traits of a proper dive watch. Rather counterintuitively, I’d actually imagine that the Diver [Air] would be most legible in the dark, as there would be no possible way of confusing its hands with its triangular movement bridges, and you would basically just be looking at the Super-LumiNova inlays that furnish its hands, hour markers, and bezel insert. That said, skeletonized watches are fundamentally less legible than their solid-dial counterparts, and it is fairly easy to overlook this one shortcoming given that the Diver [Air] was never designed for maximum legibility, but rather to claim the number one spot as the world’s lightest mechanical dive watch.

The first time that I ever experienced the cognitive dissonance created by an ultra-light watch was when I handled one of the early RM 27 “Rafael Nadal” models from Richard Mille. However, despite being stunned and thoroughly impressed by how something that size could weigh so little, the six-figure price tag attached to the watch quickly tempered my excitement. Aside from firmly being out of reach from a financial standpoint, the incredible cost of the model also made it much easier for me to rationalize how the brand could achieve such an impressive feat of engineering. Simply put, if a wristwatch costs as much as a house, virtually anything should be within the realm of possibility, and this ultimately makes an astonishing technological accomplishment seem far less impressive.

The Ulysse Nardin Diver [Air] (ref. ref. 3743-170-2A/0A) offers the same weight-related cognitive dissonance as other ultra-light timepieces, and this is further compounded by the fact that it makes zero compromises when it comes to shock and water resistance. However, arguably the most impressive aspect of the watch is that the Diver [Air] costs $38,000 USD, and while this is undeniably quite a lot of money, it is also less than half of what I initially had expected. Additionally, instead of being some limited-edition “halo piece” that is effectively little more than a concept watch, the Diver [Air] is joining the lineup as a standard-production model, and this speaks volumes about the level of confidence that Ulysse Nardin has in its ultra-light technology. Although it may not adhere to traditional notions of luxury, the Diver [Air] is undeniably impressive, and it was easily one of personal favorite releases from Watches & Wonders 2025. For more information, please visit the Ulysse Nardin website.

The photos in this article were shot on a Leica Q3, provided by Leica for Watches and Wonders 2025.