It Can Dive As Deep As The Mountain Is High: A Hands-On With The Montblanc Iced Sea 0 Oxygen Deep 4810

The new Montblanc Iced Sea 0 Oxygen Deep 4810 might be the perfect watch for spec-loving divers. Let’s look at the data, the numbers, and the cold, hard facts. Montblanc’s latest dive watch, the flagship of the newly formed Iced Sea collection, has a 43 × 19.4mm case containing no oxygen and is water resistant to 4,810 meters. Yes, 4,810 meters is the height of Western Europe’s highest mountain, which the brand is named after. The watch also has a COSC-certified automatic movement inside, and its price stays beneath the 10K mark in both euros and US dollars. This is a dive watch that wants to play with the big boys. Do you want to find out if it can?

Let’s continue with the numbers and the objective facts for now. The emotional part will follow shortly. The Montblanc Iced Sea 0 Oxygen Deep 4810 ref. 133268 is an ISO 6425:2018-compliant professional dive watch that costs €8,900 / US$9,100. Inside its incredibly water-resistant case beats the automatic caliber MB 29.29. This Sellita SW300-based ValFleurier movement is also in use (albeit with different decorations and branding) with fellow Richemont brands Baume & Mercier, Cartier, and Panerai. It’s a 21-jewel caliber with 198 components that will give you up to five days (120 hours) of power reserve. The 4Hz movement is also a COSC-certified chronometer, meaning it’s accurate to within +6/-4 seconds per day.

Some more hard facts about the Montblanc Iced Sea 0 Oxygen Deep 4810

The Iced Sea 0 Oxygen Deep 4810’s Grade 5 titanium case is decorated with vertical satin brushing and shows a polished bevel on the lugs, accentuating the curved profile. The screw-in case back and screw-down crown are also in the same titanium alloy. As you may know, Grade 5 titanium is not just light and antiallergenic. Since the alloy consists of close to 90% titanium, 6% aluminum, 4% vanadium, and small traces of iron and oxygen, it also reacts well to finishing. After being polished, it will show a luscious sheen. But let’s get back to some more functional facts, such as the 0 Oxygen case.

As the name suggests, there is no oxygen inside the Iced Sea 0 Oxygen Deep 4810’s case. Why? That’s because oxygen could cause fogging during drastic temperature changes, which leads to a poorly legible dial — dangerous! But fog is also moisture, and that could cause oxidation of the delicate components inside the case. How does Montblanc get rid of the oxygen? By filling up a tank with nitrogen (which is not as dense), sealing it, and then encasing the watch inside that tank.

You might wonder if the watch has a helium escape valve. It doesn’t. If it had such a valve that opened during decompression, some oxygen would get into the case. And that’s exactly what the Montblanc engineers don’t want.

Living up to certain standards

As mentioned earlier, the Iced Sea 0 Oxygen Deep 4810 conforms to the ISO 6425:2018 standard. This means it can withstand depths of at least 100 meters (ha!) and is outfitted with a secured measuring system to indicate the diving time. In the case of this Montblanc watch and many other pro divers, that system takes the form of a unidirectional dive bezel. The ISO standard also requires that the measuring device be visible in the dark, and of course, the flagship of the Iced Sea range complies.

Instead of the ceramic bezel insert from the shallow divers in the “MB” catalog, this deep-diving reference features an anodized aluminum one with lume-filled markers. According to MB, aluminum is more resistant to extreme conditions than ceramic, such as pressure, sharp objects like rocks, or other mysterious and dangerous stuff that lurks in the undiscovered deep.

How does it wear?

On the wrist, the watch looks big. It’s too big to wear casually on my wrist, for sure. But just like comparable watches from Rolex, Blancpain, Omega, and Oris — you figure out which models I’m referring to — the watch is intended to dive deep into uncharted waters on the wrist of bold and brash divers. Strolling down the boulevard is merely a secondary task. Having said that, the majority of big dive watches never see the action they deserve. With that in mind, the questions “How does it feel?” and “How does it compare?” are fair.

Combining a titanium case and a rubber strap makes the watch very easy to wear. Yes, it feels good on the wrist, especially with no cuff to worry about. In my opinion, this is a short-sleeve timepiece. The amount of details also creates some sort of feel-good vibe. Montblanc certainly did its very best to offer a lot of captivating visual elements. Although the rubber feels good and wears well, it also features a steel folding clasp with a fine-adjustment system. A solid, simple, and strong-looking pin buckle in titanium would have worked better with the looks and style of the watch, but that might be just my opinion.

Visual treats

The “frozen” and simultaneously smoky-blue dial shows a pattern made with an old and almost-forgotten technique called gratté-boisé. This involves a wooden tool that scratches the surface of the brass dial. But it looks less present, subtler, and more sophisticated than, for instance, the gratté-boisé dial of the 41mm 1858 Iced Sea I reviewed last year. The dial’s glacial pattern is still inspired by the Mer de Glace (Sea of Ice), the main glacier of the Mont-Blanc massif, but it now looks less rough and prominent.

Montblanc has been presenting us with some mighty fine case backs in recent years. Do you remember the decoration on the back of the 1858 Geosphere Limited Edition 1858? I wanted to wear that watch upside down because of its vibrant and colorful depiction of the Gobi Desert’s famous Flaming Cliffs in Mongolia on the back. The visual treat on the case back of the capable Iced Sea 0 Oxygen Deep 4810 is a three-dimensional depiction of what you see when you dive under the ice. The colored relief comes to life thanks to laser-generated oxidization that creates shiny and matte finishes.

How does it compare?

Strictly looking at the numbers, the Montblanc Iced Sea 0 Oxygen Deep 4810 can compete with all the super deluxe deep-diving tool watches of Switzerland’s most prestigious and respected watch brands. And it does so with a lighter price tag than them — except for the Oris Aquis Pro 4000M, but that watch has a ginormous 49.5mm case and, therefore, also can’t be fairly compared to the Iced Sea 0 Oxygen Deep 4810.

But can the Iced Sea 0 Oxygen Deep 4810 compete with the 45.5mm Omega Seamaster Planet Ocean 6000M Ultra Deep, 45mm Blancpain Fifty Fathoms, and 44mm Rolex Deepsea? I think I know your answer, but I would still love to read your response in the comments below. But you’ll have to admit that, on paper, the deep-diving Montblanc can. Unlike the deep sea, where functional capabilities matter the most, on the surface, image rules. Will Montblanc ever reach the same levels of prestige as the historical watch-only brands? Maybe it will when hell freezes over. And when that happens, the Montblanc Iced Sea 0 Oxygen Deep 4810 will have a dial that fits right in.