Montblanc’s Deep Diver, The Iced Sea 0 Oxygen Deep 4810

A deep dive watch from a brand with a name referring to Europe’s highest mountain, specialized in making high-end fountain pens…? Surprising, to say the least. Surely, there’s more to Montblanc than what I just described. Indeed, the brand has long been active in watchmaking, producing appealing dress watches and superb chronographs equipped with Minerva movements. But a deep dive watch, capable of going as deep as the height of the Mont-Blanc mountain? This is new. And that’s not the only thing to know about this Iced Sea 0 Oxygen Deep 4810.

After some years of searching itself, producing classic watches with vintage inspiration and high-complications, but also at some point car-inspired models, tourbillons, world-timers and automatons, the brand has, for the past 2 to 3 years, refocussed its collection with a focus on sports watches inspired by mountaineering – with the 1858 collection. In 2022, Montblanc decided to explore new territories, somehow the opposite (or complementary) of this adventure collection. When one was meant to explore the heights, the other one was designed to go deep underwater. Over the last 2 years, the Montblanc Iced Sea has become a fairly important collection for the brand, and this year MB has decided to go deeper. Much deeper.

The name of this new model, Iced Sea 0 Oxygen Deep 4810, says most of what needs to be known about the watch. It’s part of the Iced Sea collection, it features the brand’s “Zero Oxygen” concept and it has a rather impressive depth rate of 4,810m… Why this number? Well, that’s the height of Europe’s highest mountain, the Mont-Blanc. Looking at this new addition to the collection, the connection with the previous models is undeniable. So much so that, at first, you’ll hardly notice that we’re talking about one of the rare watches in production capable of withstanding such underwater pressure. It looks like a beefed-up version of the classic 300m version, but nothing like a testosterone-fed instrument. This Iced Sea 0 Oxygen Deep 4810, from a distance, somehow flies under the radar.

Well, until you strap it on the wrist, and see what’s printed on the dial at 6 o’clock. What we’re looking at is far from a svelte dressy watch. But at 43mm in diameter, it remains fairly reasonable, with curved lugs hugging the wrist and a relatively short case. The height of the case is substantial, as you’d expect from a watch capable of resisting pressures of over 480 bars. It measures 19.4mm in height. I know, it sounds gigantic, but the watch is equipped with a fairly domed caseback that somehow absorbs a few millimetres. The result, on the wrist, is a feeling of a 16mm watch. It’s still a watch with much wrist-presence, but considering other deep divers – such as the Rolex Deepsea, the Omega Ultra-Deep or the Delma Blue Shark IV – it remains in the same range or slightly more wearable.

Another pleasant point with this range-topping Montblanc Iced Sea is the use of titanium for the case, making it lighter than the size would suggest, and resistant to corrosion. The rest of the watch is fairly subtle, without any exaggeration of the deep diver concept. The screw-down crown is protected by lateral guards, the dial is covered by a thick sapphire crystal (but not overly thick, and without much distortion) and the case retains most design cues from the collection in a restrained way. The unidirectional bezel is equipped with an aluminium insert, a surprising choice when the classic 300m models come with a ceramic bezel. But design-wise, I do understand and like this choice, giving a more matte and more instrumental look to this deep diver. Last, this watch is ISO 6425 compliant.

Another specificity of this watch, and many of Montblanc’s sports watches, is the Zero Oxygen concept. While usually experienced on high-altitude exploration models, it is now offered on a watch that’s meant to go deep underwater. The idea is to remove oxygen from the case, and the result is that it eliminates fogging, which can occur with drastic temperature changes, but also prevents oxidization. Without oxygen, all the components last longer and will provide continued precision over time.

For the dial of its deep diver, Montblanc retains the iced water texture found on the classic 300m watches, which is said to be inspired by one of the Mont-Blanc mountain’s largest glaciers – the Mer de Glace (iced sea) – with an interlocking network of crystals. The dial is made with a gratté-boisé technique, a time-consuming process that adds texture and depth. The blue tone is here darker than other models from the collection, reflecting the colour of the sea at greater depths, and it features a smoked effect, with a darker colour on the periphery (sfumato effect). The dial remains otherwise clean and classic, with applied Arabic numerals, hour markers and hands filled with blue-emitting Super-LumiNova. A date window sits at 3 o’clock… a feature that could have been removed in the context of a deep dive watch.

Inside the case is the automatic calibre MB 29.29, produced by ValFleurier and based on the Baumatic architecture. Running at 4Hz, this modern movement boasts a generous 5-day power reserve and is certified chronometer by the COSC. The watch also undergoes the Montblanc Laboratory Test. The movement is hidden under a bold caseback with 3D engraving, a texture that is achieved by a process of laser-generated oxidization that structures the metal with both matte and shiny finishes.

Worn on a black rubber strap closed by a folding clasp with an on-the-fly fine adjustment device, the Montblanc Iced Sea 0 Oxygen Deep 4810 is a surprising release from a brand that’s not often associated with instrument watches. It is nevertheless quite an achieved piece, with discreet look and a price to match the specs – EUR 8,900. For more details, please visit www.montblanc.com.