
The Hydrosphere’s retrograde hand and unique bezel could either be ingenious designs or a confusing learning curve
Any timepiece that offers something distinct or eye-catching—whether through its design, external features, or defined inspirations—has my attention. So when I saw that RESERVOIR’s watches only had one hand to tell the time, I had to figure out how such a mechanism worked.
RESERVOIR is a relative newcomer in the watchmaking world—it has only been around for six years. Though in that span of time, it’s set itself apart with its unique designs. Immediately, you’ll notice that these Swiss-made and French-designed timepieces are inspired by vintage meters and gauges, which lends itself to a few interesting mechanisms and design choices.

Their watches are somewhat middling when it comes to cost—at least, as far as luxury watch prices go—even with their high-level features. On the founders’ part, these design and cost options were deliberate: in a previous interview with MANTLE, Business Development Director Francois Nakkachdji shared that they wanted to target watch enthusiasts and collectors who marvel at owning a timepiece with advanced complications, but at a good price.

Their Hydrosphere line—the Blackfin watch, in particular—grabbed the attention of watch aficionados around two years ago when it got nominated for an award in the Diver’s Category of the Grand Prix d’Horlogerie de Gèneve: the Oscars of watchmaking.
This year, the Hydrosphere introduces a new, limited-edition variant in the line-up: the Hydrosphere Bronze X REVOLUTION, clad in bronze and rose gold finishes. Aptly called “The Maldives Edition,” its colors are reminiscent of the glistening colors of a tropical summer sunset by the ocean.
But, really—even if you’re not going to dive with it, the Bronze x REVOLUTION is a striking watch that you would want to take on long walks by the shore, drives along the coastline, or even lazy al fresco lunches in the rustic countryside. Add the fact that it’s vintage-inspired, and you have a timepiece that makes an impression not only for its mechanisms, but also for its aesthetics.
So how does the Hydrosphere work, exactly?
Telling the minutes with the watch is straightforward enough. The retrograde minute hand travels from 0 to 60 across a 240-degree radial, which springs back to 0 at the turn of the hour. In turn, the hour is displayed in Arabic numerals on a disc at the lower-central part of the watch.
The retrograde hand is quite quaint and ingenious, mimicking the movement of a pressure gauge or speedometer to tell the time—in fact, some of the brand’s designs carry several racing elements or are inspired by vintage instrument dials.

But then this raises a question: how can a minute hand that springs back to 0—instead of going around and around—tell time if the mechanism gets installed in a watch meant for diving?
This is where the RESERVOIR Hydrosphere’s unique bezel comes in. And admittedly, it’s quite a nifty solution, if not an initially befuddling one.
The Swiss brand’s dive watches have two time tracks in their bezels: one for dives that start before the 45th minute of the hour, and one for dives that happen after. The red one is marked for times before 45 minutes, while the blue ones are for times after 45.

The trackers are then divided in 5-minute increments, with the 15-minute mark indicated for both scales. The bezel allows for 30-minute dive sessions.
The earlier case (before 45) is simple enough. By turning the bezel to align the triangle marker with the minute hand, you can tell how long you’ve been in the water like you would in a normal dive watch, using the red-colored tracker.
The latter case (after 45) requires a bit of a learning curve. While you still turn the bezel to align the marker to the minute hand, you’ll have to look now at the blue tracker. Since the retrograde minute hand and the calibrations only go up to 240 degrees, the first red tracker won’t be able to count the minutes that have elapsed—instead, the second blue one picks up from where the red tracker finished counting.
It may sound confusing at first, but it makes sense after studying the bezel carefully and seeing how the two trackers supplement each other to tell accurate dive time.
One could call this adjustment an inspired piece of work, but it also raises the question of somehow sacrificing simplicity for a standout design. But getting over this learning curve might just be worth it, considering how gorgeous RESERVOIR’s dive watches are, especially the Bronze X REVOLUTION variant.

The Hydrosphere Bronze X REVOLUTION watch is like a vintage pressure gauge polished to pristine conditions. At 45mm, it’s a bit on the larger side, but the watches’ bronze and rose gold finishes are quite the looker. For a dive watch, I could see these colors glistening when the sun shines on them, just like a gorgeous sunset on the ocean’s horizon.
For all our praise for its casing, does it matter if it’s bronze, steel, or gold? For those who are particular with how their watch ages, yes. Bronze ages and develops a patina,a film that usually grows over time on copper or bronze, acquired by age and exposure.
As no two bronze cases form the same pattern—not to mention that the patina colors can be gorgeous in their own right—you can think of this aging process as the watch’s natural way of personalization, akin to Japanese denim. How it changes over time depends on the wearer’s lifestyle—if they always take the watch to dives or wear it casually throughout the day—so that adds a more personal touch.
For their ingenuity and willingness to push the envelope for telling time, RESERVOIR merits another look—especially since they’ve worked around the diver’s conundrum for a watch that doesn’t complete the whole 360 degrees.
Maybe I could say this because I’m just looking at it now instead of using it in the depths of the ocean, but I think it’s worth going through the trouble of learning its unique mechanism, if only to dive with a timepiece that looks like a beautiful glistening sunset on your wrist.