The Ulysse Nardin AIR - The World's Lightest Mechanical Dive Watch

In 2021, the brand introduced the Diver X Skeleton, a timepiece that revolutionised the industry by combining skeletonisation with a dive watch. In fact, today, many collectors acquire a dive watch as a robust, everyday timepiece that can withstand impact, and they often also add a high horology piece to their collection—a prized jewel worn with care. Ulysse Nardin envisioned a watch that seamlessly combines the best of both worlds.

That was a breakthrough, but this is Ulysse Nardin, and so laurels are definitely not for resting on. To truly make this the ultimate high horology sport watch, it could be even better. Stronger, sleeker—but most importantly, lighter.

Introducing the new Diver [AIR], a skeletonised high horology sport watch designed for the extremes, that is going to have its weight cut in half.

For perspective, the Ulysse Nardin Diver 44mm released in 2019 weighs 120.5g, as would be expected for a sturdy, robust dive watch. The Diver X Skeleton from 2021 cuts an impressive 15g off that mass for a total weight of 105.8g, which, considering how much empty space there is inside that skeletonised calibre, demonstrates how much of a challenge cutting back on weight really is. And yet the Diver [AIR] manages to lose an incredible 68.6g from the Diver 44mm and comes in at less than half of the Diver X Skeleton, which seems, frankly, unrealistic.

Building upon the foundation of the Diver X Skeleton UN-372 movement, Ulysse Nardin developed a new, innovative, high- tech calibre, the UN-374, which had to be entirely rethought and redesigned. To achieve the Diver [AIR]’s exceptionally light weight of just 52g, including the strap, and under 46g without it, material had to be removed from the Diver X Skeleton’s calibre, while ensuring the watch’s reliability and performance remained uncompromised.

To do so, Ulysse Nardin’s designers endeavoured to remove material in the movement, to counterintuitively make it, somehow, even stronger. More robust. As mass was reduced, what was left was also reconfigured to bring further resilience to its structure. This was done by using the slender bridges to form triangles, a rigid shape found in engineering and architecture to resist bending and warping, an expertise Ulysse Nardin has developed for over thirty years since its first skeletonised watch.

Despite the space inside the watch being 80% air and just 20% material (the watch movement), the highly skeletonised calibre UN-374 can withstand an impact of an impressive 5’000g. It has also been tested for general knocks and vibrations, cycling thousands of shocks over several days, and not just in the lab, but in real-world use too, putting the watch through its paces to prove it can be worthy of the Ulysse Nardin name.

A closer look at the new calibre reveals the extent to which Ulysse Nardin has gone to reduce mass without compromising performance. The bridges are barely a few millimetres wide, hollowed out to save even more weight, while the winding rotor has been minimised 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. Material has even been stripped from the barrel itself to lighten it further, bringing the total weight of the calibre down to just 7g—less than half the weight of the already lightweight Diver Skeleton X’s movement. Some components have also been redesigned—not only for optimal performance but to achieve a visual balance that enhances its overall appeal. After all, who doesn’t like a watch that looks as good as it performs?

You may be wondering why Ulysse Nardin chose not to remove the automatic winding mechanism from the Diver [AIR] to reduce weight further. The answer lies in the stringent official standards that a dive watch must meet, with automatic winding being one of those essential criteria. Additionally, the calibre UN-374 boasts an impressive 90-hour power reserve, thanks to its innovative flying barrel. The Diver [AIR] is equipped with two ultralight, elasticated straps in white and orange for comfort, fastened with a scratch closing for added practicality. These straps are easily interchangeable, without the need for any tools, ensuring the watch remains as versatile as it is functional.