Ulysse Nardin Diver [AIR]: The Lightest Mechanical Dive Watch To Date
Unveiled at Watches and Wonders 2025, the Ulysse Nardin Diver [AIR] redefines the boundaries of mechanical dive watch engineering. With a total weight of just 52 grams—or 46 grams when worn without the strap—this 44mm timepiece stands as the lightest mechanical diver in the world (claimed by brand).
Lightweight Engineering Through Modular Construction
At the heart of this achievement is a modular construction that strategically combines titanium with innovative, recycled composite materials. The central structure of the case is crafted from 90% recycled titanium, providing both structural integrity and water resistance rated to 200 meters. Surrounding this core, the side components, including the lugs, are formed using Nylo-Foil—a sustainable material composed of recycled fishing nets and upcycled carbon fiber.
The watch’s unidirectional bezel features a luminous insert forged from compressed carbon fiber. This material is repurposed from carbon elements salvaged from retired IMOCA sailing boats. The result is a surface with a unique, randomized pattern characteristic of forged carbon.
UN-374 Skeletonized Movement: A Showcase of Material Efficiency
Inside the Diver [AIR] is Ulysse Nardin’s newly developed UN-374 caliber, a skeletonized movement engineered specifically for extreme weight reduction. While inspired by the UN-372 movement seen in earlier models, this new caliber represents a significant evolution in both design and material efficiency.
Among the most noticeable changes is the removal of the top movement plate, which previously displayed the brand’s signature “X” motif. Its absence opens up a more expansive view of the movement architecture. The bridges, now made of titanium, have been narrowed and hollowed to eliminate excess material. Even the mainspring barrel—responsible for an extended 90-hour power reserve—has been lightened. It is now suspended in a flying configuration and features wheel-like spokes, with both the top and bottom surfaces hollowed out.
The movement is also equipped with a silicon escapement, underscoring Ulysse Nardin’s long-standing leadership in the use of advanced materials in traditional watchmaking.
Altogether, the UN-374 caliber weighs just 7 grams. According to the brand, the Diver [AIR] is composed of approximately 80% air and 20% mechanical material—an unprecedented ratio in a professional-grade dive watch.
Shock Resistance and Performance
Despite its ultra-lightweight and openworked design, the Diver [AIR] does not sacrifice durability. Ulysse Nardin states that the watch can withstand impacts up to 5000g, placing it on par with other high-performance dive watches that meet rigorous certification standards such as METAS.
Availability and Pricing
The Ulysse Nardin Diver [AIR], reference 3743-170-2A/0A, is now available for purchase. It comes fitted with a lightweight elastic fabric strap and is priced at USD 38,000.
Read more here.
General Specifications:
Brand: Ulysse Nardin
Model: Diver [Air]
Reference: 3743-170-2A/0A
Dial: Skeletonized
Lume: Super-LumiNova
Case Material: Carbon fiber and titanium
Case Dimensions: 44 mm Diameter, 14.70 mm thickness
Crystal: Sapphire Glass
Case Back: Sapphire Glass
Water Resistance: 200 Meters
Strap: Orange and white elastic fabric straps
Calibre: UN-374
Functions: Hours, minutes, seconds
Winding: Automatic
Frequency: 3 Hz (21,600 Vph)
Power Reserve: 90 Hours
Price: USD 38,000
Limited Edition: No
Availability: Now
