Startlingly capable, the Bühlmann Decompression 02 diver’s companion is more than just another 300m steel sport watch with a bezel. Some brands have long since folded practical depth-tracking into the dive-watch equation, and this model takes that philosophy to a notably advanced level. As its name implies, the Decompression 02 is the evolved successor to the Decompression 01, conceived as a serious diving instrument rather than a casual timepiece. It builds on the idea of a professional calculator for decompression, drawing inspiration from Albert Bühlmann’s circular decompression concepts and packing in 17 common dive profiles plus a “fly-no-fly” indicator for post-dive planning.
Albert A. Bühlmann (1923–1994) was a Swiss physician whose decompression research at Zürich University Hospital reshaped how divers ascend, spanning commercial, military, and recreational realms. His ZH-L16 decompression algorithm underpins many decompression tables. In tribute to his legacy, Watch Angels introduced the Decompression 01 in 2021, and this new Decompression 02 expands that concept with richer functionality.
A decompression table is a safety guide that helps divers plan safe ascents and minimize the risk of decompression sickness by showing the maximum allowable bottom time at various depths and indicating when and how long stops are needed during ascent. While modern dive computers compute this in real time, these tables remain a foundational reference for deliberate, controlled nitrogen release.
A bold, instrument-inspired silhouette
Before diving into the watch’s specialized features, the first thing that commands attention is its technical, formidable presence. The three-crown case design nods to vintage bullhead chronographs from the 1970s. Crafted from stainless steel, the watch wears with a substantial, rugged heft on the wrist. At 48.5mm in diameter, it’s unapologetically bold—more at home on a diver’s suit than at the yacht club.
The crowns serve distinct purposes: the center crown winds and sets the time; the right-hand crown governs the twin decompression dial; and the left-hand crown locks or unlocks the twin decompression bezel. Eight screws secure the caseback, which is slightly concave for comfort, and the case itself sits angled by 5 degrees to aid legibility.
A substantial 575m water resistance nods to Bühlmann’s Zürich hyperbaric testing heritage, signaling readiness to accompany divers far beyond the usual recreational depth range.
Helium management and minute-first legibility
Designed as a professional instrument, the Decompression 02 includes a helium relief feature integrated into the left crown. For depths beyond 70 meters, where air pressures become hazardous, divers may breathe helium-enriched gas in pressurized environments. Helium’s tiny size allows it to seep into the watch case, and without a relief valve, pressure changes during ascent could compromise the crystal.
As expected for a true dive watch, the Decompression 02 emphasizes legible time-reading at a glance. The minute hand is prominent for timing safety-critical dive segments, while the hour hand is kept deliberately minimalist. The seconds hand features a red, luminescent, arrow-tipped end, crucial for confirming that the watch remains active during a dive, since a stopped watch can lead to incorrect elapsed-time readings and unsafe decompression decisions.
Twin decompression bezel and Twin Decompression Dial
The standout feature is the Bühlmann Twin Safety Bezel, which allows separate tracking of total dive time (TDT) and decompression stops (DS), each with its own independent direction lock. The DS function engages only when the 11 o’clock crown is released.
The watch’s 17 decompression-stop times derive from Dr. A. Bühlmann’s decompression tables and are displayed on the Bühlmann Twin Dive Dial. A selectable dive profile is chosen by rotating the lower dial via the right crown, while the related data appears in the cut-out at 6 o’clock.
In practice, the inner total-dive-time bezel is reset to zero by aligning the 0 marker with the minute hand at dive start. As depth changes, the chosen profile guides monitoring; when returning to the surface, the decompression-stop schedule is displayed using the outer bezel at 9m, 6m, and 3m markers.
The Decompression 02 emphasizes “Golden Zone” profiles—17 common single-tank dives up to 39 meters, suitable for altitudes from sea level to 700 meters above. The dial itself communicates these profile options visually.
A rare finish at the end of the dive
At the conclusion of a dive, the bottom dial can be set to a “Fly-no-Fly” position, with the corresponding indicator moved to “no-fly” using the center crown’s date-setting function. An arrow points toward a red zone, indicating a mandatory no-fly period. Once the 24-hour no-fly window has elapsed, the indicator should move toward green, signaling it’s generally safe to fly; note that the date wheel may advance in 12-hour jumps, so the “min” indicator serves as a caution that a check is needed if the wheel hasn’t moved yet.
Movement, availability, and price
Inside the Bühlmann Decompression 02 sits a reliable SW-300 caliber—an ETA 2892-style movement produced by Sellita. It measures 25.60mm, runs at 4 Hz, and delivers at least 50 hours of power reserve. A stop-seconds function supports precise setting, which is crucial for aligning dive timing with plan accuracy.
The watch ships on a perforated rubber strap designed for a wide range of wear, with an articulated buckle side and a tail that integrates into the lugs. The clasp bears the brand logo in engraved form. This piece is produced in a limited edition of 575 units and carries a suggested price of CHF 3,990. Availability is exclusive to watchangels.ch.
A portion of each sale supports DAN Europe Medical Research Foundation as part of ongoing efforts to refine the perfect decompression algorithm.
