Montblanc Iced Sea 0 Oxygen 38mm Adopts ISO 6425 Certification with Compact Design

At Watches and Wonders 2025, Montblanc introduced a significant addition to its Iced Sea dive watch lineup: the Iced Sea 0 Oxygen 38mm. The new models bring the collection's glacier-inspired aesthetics and professional diving credentials into a more compact case size, while integrating the brand's advanced 0 Oxygen technology for enhanced durability in extreme conditions.

ISO 6425 Certification and Diving Standards

According to aBlogtoWatch, the new 38mm Iced Sea models adhere to the ISO 6425 standard for certified divers' watches. This internationally recognized specification requires watches to meet rigorous performance criteria, including water resistance testing at 125% of the rated depth, resistance to thermal shock, and magnetic field protection. ISO 6425 certification is the benchmark standard that separates genuine professional dive watches from mere water-resistant timepieces.

Montblanc's Iced Sea collection, first introduced in 2022, was designed from the outset with these professional standards in mind. The 38mm models maintain the same ISO 6425 compliance as their 41mm predecessors, ensuring that the smaller case size does not compromise diving performance.

Key Specifications

0 Oxygen Technology

According to Montblanc, the 0 Oxygen technology eliminates all oxygen from inside the case, preventing fogging due to sudden temperature changes and protecting internal components from oxidation. This advancement is particularly relevant for divers operating in extreme cold environments. 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. Additionally, owners of previous editions will have the option to upgrade their watches by sending them to a Richemont service center or a Montblanc boutique.

Dial Design and Finishing

The two new dial colors—Glacier White and Glacier Light Blue—are crafted using the intricate gratté-boisé technique, which creates a textured effect reminiscent of real ice. This process takes four times longer to complete than a standard dial, requiring over 30 distinct steps to achieve its frozen aesthetic. The light blue variant debuts with a sfumato effect, an Italian technique that blends colors seamlessly for a soft, smoky transition.

Pricing and Availability

The Montblanc Iced Sea 0 Oxygen 38mm Glacier White (ref. 134024) and Glacier Blue (ref. 134022) are priced at $3,460 on a rubber strap or $3,660 on a stainless steel bracelet. Both models are available now through authorized Montblanc dealers worldwide.

Frequently Asked Questions

What is ISO 6425 certification?

ISO 6425 is the international standard that defines the requirements for divers' watches. It specifies testing for water resistance, thermal shock, magnetic resistance, and legibility in low-light conditions. Watches certified to ISO 6425 must be individually tested and marked as "Diver's Watch."

How does the 0 Oxygen technology benefit divers?

The 0 Oxygen technology eliminates oxygen from the case interior, preventing condensation and fogging during rapid temperature changes—common in deep diving. It also protects internal components from oxidation over time, extending the movement's service life.

Is the 38mm Iced Sea suitable for professional diving?

Yes. Despite the smaller case size, the 38mm Iced Sea maintains full ISO 6425 certification, meaning it meets all the same professional diving standards as the larger 41mm models.

Source: aBlogtoWatch, March 31, 2025 — Original Article

For more on dive watch standards, see our guide to understanding dive watch specifications and watch certifications explained.