The recreational dive watch market has become flooded with sleek throwbacks to 1960s skin divers and stylish desk-diving pieces that never see saltwater. But there's a new player that refuses to play by those rules. The Bühlmann Decompression 02 doesn't care about fitting under your shirt cuff, and it certainly isn't trying to be subtle.
At 48.5mm across and 17mm thick, this Swiss-made timepiece weighs in at 204 grams on its rubber strap. For comparison, that's heavier than Omega's latest Ploprof at 183 grams. This isn't a watch that "wears smaller than its measurements suggest." It's a bruiser, plain and simple, and it makes no apologies for its size.
The Decompression 02 comes from Bühlmann, a sub-brand operating under Watch Angels, a Swiss manufacturer run by CEO Guido Benedini. "Watch Angels is a vertically integrated watch enthusiasts' platform that brings alive meaningful watches, brands, and horological heritage projects," Benedini explains. "Our mission is to never produce a boring watch."
Built on Science, Not Style
What sets this piece apart from typical dive watches isn't just its dimensions. The Decompression 02 was developed in collaboration with the son of Dr. Albert A. Bühlmann, whose name carries serious weight in the diving community. Between the late 1950s and 1980s, Dr. Bühlmann developed the ZH-L16 decompression model, which unified decompression theory across both sea-level and altitude diving.
"The Bühlmann Decompression 01 watch was developed in 2021 as a Watch Angels project," Benedini says, "in collaboration with the son of Dr. A Bühlmann, with the idea of integrating Swiss decompression science and dive safety legacy into a mechanical diving watch." The Decompression 02 represents a refinement of that original concept.
This watch focuses on something most dive watches ignore: the ascent phase of a dive plan. While modern dive computers calculate everything on the fly, the Deco 2 takes a different approach. You interact with it before the dive, lock it down, and then use it as a reference framework as the dive unfolds. It's closer to professional dive tables than to a modern computer, but translated into something tactile and mechanical.
Understanding the Beast
The first thing you notice when unboxing the Decompression 02 is that the packaging doesn't match the seriousness of what's inside. The box is generic, almost flimsy, similar to how Seiko often foregoes fancy packaging and lets the watch speak for itself. And once you strap on this 204-gram instrument, it definitely has something to say.
The ice-blue dial delivers a fresh punch, echoing colorful Doxas and the Omega Ploprof, but with a distinctly modern vibe. The watch features a 5-degree case inclination that makes it resemble an intricate dash instrument. The screw-fixed case back is polished and concave, creating an ergonomic, if weighty, presence on the wrist.
Two side crowns sit at approximately 1 and 11 o'clock, recessed into scalloped openings in the lugs. The articulated lugs measure 19-20mm in theory, but the proprietary vented rubber strap embraces their tips, making the effective width 26mm that tapers down to 22mm. Twin lockable bezels frame the deep dial and inner decompression scale, with the outer ceramic dive bezel featuring engraved markings filled with green-glowing lume.
The bezels themselves are adjusted by stacked castellated and coin-edge rings that work well with gloves and offer precise clicks with rock-solid haptics. The fit and finishing are impressive for its sub-$5,000 price point, showing a few glints of polish on the steel case.
A Dial That Demands Attention
The dial is remarkably deep, with engraved text on its vertical, brushed rehaut. But the real focal point is the rotatable decompression scale beneath a centrally fixed ice-blue dial with matte and sunray-brushed finishes. A stepped, wedge-shaped opening at 6 o'clock lets you view the decompression scale you've chosen for your dive, featuring sharp printed text and lume-filled applied indices.
Like the Ploprof and Doxa dive watches, the hour hand is diminutive, completely overshadowed by the elaborate, diameter-filling yellow minute hand with its red arrow tip. A needle seconds pointer features another bold red, lumed arrow tip, with these colors adding life to what could have been purely monochromatic.
"We built the Decompression 02 without any concessions to established dive watch design conventions," Benedini states. "This watch can be defined as mechanical tool art because it communicates its purpose so clearly."
How It Actually Works
The Bühlmann Decompression 02 is designed to operate within what's called the "Golden Zone" of recreational diving, where planning, discipline, and conservative ascent rates matter. It doesn't calculate or adapt on the fly. Instead, it rewards preparation and respect for the physics involved.
Three top-mounted crowns control different functions. The central crown (number 2) sets the time and manually winds the Sellita SW-300 movement. It's also used for setting the fly/no-fly function. Before a dive, you unscrew crown number 3 at 1 o'clock to rotate the decompression dial beneath the blue center dial, displaying the depth and bottom time combination you need. Pushing it in and screwing it locks the deco dial for diving.
Crown 1 at 11 o'clock unlocks and locks the TDT (total dive time) inner bezel, allowing you to rotate it and align it with the minute hand. This lets you measure descent time and bottom time using the TDT bezel, and measure ascent rate using the seconds hand at no more than 10 meters per minute.
Once you reach the first decompression stop, you turn the outer DS bezel clockwise, aligning the zero marker with the minute hand to measure the duration of the decompression stop. You repeat this process for your ascent rate using the seconds hand, then repeat it for each additional decompression stop using the DS bezel.
After the dive, the Fly/No-Fly indicator serves as a visual reminder of surface interval discipline, helping you decide when it's safe to fly after diving.
Critical Safety Information
There's one absolute rule: once you're underwater, the crowns stay sealed and locked. Opening a crown below the surface risks compromising the watch entirely.
It's crucial to understand what this watch is and isn't. The Bühlmann Decompression 02 is not a dive computer, nor is it certified as a professional diving instrument under ISO standards. It's designed as a planning and reference tool, not as a life-support device. It should never replace a certified dive computer, especially when diving at altitudes above 700 meters or when making decisions about flying after a dive.
The role of this watch is educational and preparatory. It doesn't make decisions for you. It's intended as a tool to help plan a safe dive profile and serve as a backup to digital dive computers. Recreational diving, as defined by organizations like PADI, is trained and intended as no-decompression diving. Divers should stay within no-decompression limits and not require decompression stops beyond the standard safety stop at 5 meters for 3 minutes. Planning specifically for decompression stops is not within the scope of recreational diving and is not recommended without technical dive training.
The Purpose Behind the Size
Some might wonder why this watch needs to be so large. Benedini's answer is straightforward. "For a watch of this kind, the primary R&D concerns have been purpose, quality, and usability, not size." The dimensions serve the function, not fashion.
The watch is tested to 575 meters and incorporates a helium valve. With articulated lugs at the top of the case, it's comfortable despite its heft. But make no mistake, this beast won't slip under any cuff. If you plan to wear it with regular clothes, be prepared to wear it on-cuff in the style of Gianni Agnelli, where it's guaranteed to be a conversation starter.
On the wrist, especially if you imagine yourself wearing a wetsuit or drysuit, the architecture makes immediate sense. The 5-degree case inclination and overall size create a presence that feels appropriate for serious diving equipment.
Opening Up a Closed Category
The Bühlmann Decompression 02 competes in a space that's largely been abandoned. While watches like the Omega Seamaster and Tudor Pelagos offer more wearable and conventional alternatives, few modern pieces focus on mechanical decompression planning. The experimental Blancpain Fifty Fathoms X Fathoms represents hardcore investment-grade territory, but the Deco 2 offers something different from the norm.
"It is a complement to digital dive computers as a back-up instrument," Benedini explains, "re-opening a category which has almost disappeared with the increasing human reliance on digital technology."
The watch operates within the Bühlmann ZH-L16 decompression model framework, with rotatable scales under the center dial making limits, stops, and ascent discipline visible rather than abstract. The intellectual foundation becomes physical, translated into something tactile, mechanical, and more versatile than modern computers for those who appreciate the mechanical solution as part of their workflow.
What's Next for Bühlmann
According to Benedini, Bühlmann Watches will transition to a standalone brand in early 2026 to focus on developing mechanical decompression and other backup dive watches. New models will continue to draw inspiration from Dr. A. Bühlmann's applied decompression science. The 2026 collection will include two watch models, expanding to four by 2028.
The Bottom Line
The Bühlmann Decompression 02 is available for CHF 3,590 until January 31st, in an edition of 575 pieces. That edition number matches its depth rating of 575 meters. A portion of each sale will be donated to the DAN Europe Medical Research Foundation to support ongoing research into the perfect decompression algorithm.
This isn't a watch for everyone. At 48.5mm and 204 grams, it demands attention and wrist real estate. The packaging is nothing special, arriving in a generic box similar to what you'd expect from affordable dive watches. But once you have it on your wrist, the purpose becomes clear.
For those who appreciate mechanical solutions in an increasingly digital world, the Decompression 02 represents something increasingly rare: a tool that makes you think about what you're doing rather than doing the thinking for you. It's not a shortcut. It's a mechanical reference that rewards preparation and understanding.
The ice-blue dial, yellow minute hand, and red-tipped seconds hand create visual interest that could have easily been lost in a purely monochrome design. The twin lockable bezels, deep dial architecture, and rotatable decompression scales all serve clear purposes. This is a watch that communicates its function immediately, even if understanding exactly how to use it requires some study.
In a world where most dive watches are fashion statements or nostalgic homages to vintage pieces, the Bühlmann Decompression 02 stands apart. It's unashamedly large, seriously engineered, and focused on a specific aspect of diving that most modern watches ignore entirely. Whether that makes it the right choice depends on what you value in a dive watch and whether you're willing to embrace something that refuses to blend in.
