Montblanc Iced Sea 0 Oxygen 38mm: A New ISO 6425 Certified Dive Watch Arrives at Watches and Wonders 2025
At Watches and Wonders 2025, Montblanc introduced a new dimension to its Iced Sea collection: the Montblanc Iced Sea 0 Oxygen 38mm. Previously available only in a 41mm case, this compact addition arrives with two striking new dial options and the brand's proprietary 0 Oxygen technology, all while maintaining full ISO 6425 certification as a professional diver's watch.
What Is the ISO 6425 Standard?
ISO 6425 is the international standard that defines the requirements for dive watches. To earn this certification, a watch must pass a series of rigorous tests including water resistance at 125% of its rated depth, resistance to thermal shock, magnetic resistance, and legibility in dark conditions. The standard also requires a unidirectional rotating bezel, luminous markers, and a minimum water resistance of 100 meters. According to Montblanc, the Iced Sea 38mm meets all of these criteria, making it a legitimate professional diving instrument rather than a mere "dive-style" watch.
0 Oxygen Technology Explained
Montblanc's 0 Oxygen technology eliminates all oxygen from inside the watch case during assembly. This innovation prevents internal fogging caused by sudden temperature changes — a critical concern for divers transitioning between warm surface conditions and cold deep water. The technology also protects internal components from oxidation, extending the movement's service life and maintaining long-term accuracy. Each watch comes with a certificate verifying the successful implementation of this technology.
Starting in April 2025, Montblanc plans to integrate 0 Oxygen technology into all newly produced Iced Sea models. Owners of previous editions will also have the option to upgrade their watches by sending them to a Richemont service center or a Montblanc boutique.
Key Specifications
| Specification | Detail |
|---|---|
| Case Diameter | 38mm |
| Case Thickness | ~12mm |
| Water Resistance | ISO 6425 Certified |
| Movement | Montblanc Caliber MB24.17 (Sellita SW200 base) |
| Power Reserve | 38 hours |
| Bezel | Unidirectional rotating, ceramic or anodized aluminum insert |
| Dial Options | Glacier White, Glacier Blue |
| Strap Options | Stainless steel bracelet or rubber strap |
Glacier-Inspired Dials
The dial colors are crafted using the intricate gratté-boisé technique, creating a textured effect reminiscent of real ice formations on the Mer de Glace glacier of the Mont Blanc Massif. This process takes four times longer than standard dial production, requiring over 30 distinct steps. The white dial marks a first for the Iced Sea collection, while the light blue variant debuts with a sfumato effect — an Italian technique that blends colors for a soft, smoky transition. All dials feature luminescent hands, indexes, and a 12 o'clock bezel marker for underwater legibility.
Caseback Design
A signature feature of the collection, the caseback showcases an intricate 3D engraving of a scuba diver beneath an iceberg. This motif reinforces the watch's connection to extreme alpine and underwater exploration.
Pricing and Availability
The Montblanc Iced Sea 0 Oxygen 38mm Glacier White (reference 134024) and Glacier Blue (reference 134022) are both priced at $3,460 on a rubber strap or $3,660 on a stainless steel bracelet. Both models are available now through Montblanc boutiques and authorized dealers worldwide.
Why This Matters for Dive Watch Enthusiasts
The 38mm case size addresses a growing demand for more compact dive watches that don't compromise on professional-grade specifications. Combined with the 0 Oxygen technology and ISO 6425 certification, Montblanc has created a serious tool watch that also works as a refined everyday timepiece. For collectors who previously found the 41mm Iced Sea too large, this new size opens the door to a watch that balances adventure-ready capability with wearable proportions.
Frequently Asked Questions
Is the Montblanc Iced Sea 38mm a real dive watch?
Yes. The Montblanc Iced Sea 38mm is fully ISO 6425 certified, meaning it has passed all international standards for professional diver's watches, including water resistance testing at 125% of rated depth, legibility requirements, and bezel functionality tests.
What does 0 Oxygen technology do?
The 0 Oxygen technology removes all oxygen from inside the watch case during assembly. This prevents internal fogging from temperature changes and protects the movement from oxidation, improving long-term reliability and accuracy.
Can existing Iced Sea owners upgrade to 0 Oxygen technology?
Yes. Starting in April 2025, owners of previous Iced Sea models can send their watches to a Richemont service center or Montblanc boutique to have the 0 Oxygen technology retrofitted.
Sources
According to aBlogtoWatch, the Montblanc Iced Sea 0 Oxygen 38mm was unveiled at Watches and Wonders 2025 with ISO 6425 certification and new glacier-inspired dial colors.
For more on dive watch standards, see our comprehensive dive watch buying guide and our explainer on ISO 6425 dive watch certification.