German watchmaking is in a healthy position. From the fine watchmaking powerhouses of Glashutte – Lange, Nomos, Glashutte Original – to the titans of Teutonic tool watches – Sinn, Mühle Glashütte, Damasko, Tutima – the country is producing some of the best known and regarded modern watches. There are many I missed, including some of the smaller production outfits like Stowa, Archimede, and Laco, which might be familiar to Time Bum readers. With all those big names out there, you might not have heard of Circula, and I am here to remedy that oversight.
Circula has been in business for over 70 years, focusing on reliable, robust tool watches. The Pforzheim manufacturer has a strong history, yet their current catalog is modern, not self-referential, and full of effervescent designs. Imagine if Sinn let the designers behind their more playful offerings have their run of the whole catalog. The resulting watches balance utilitarian purpose with a sense of joy, a combination that the ProSea embodies.
Circula offers a lot of dive watches, and the ProSea is positioned as the most capable of them all. The fully graduated and fully lumed ceramic bezel insert and bold handset scream READ ME, which is useful when using your watch to track dive duration and decompression stop intervals. While some of Circula’s other dive watches are designed to evoke midcentury sports watches, the flat planes and angles of the ProSea’s case exude indelicate sporting intent.
While it isn’t elegant, the ProSea’s 40mm wide case has some of the embellishments that are a hallmark of Circula’s design ethos. The majority of the case is matte-finished, but two inset niches along the case flanks are finished in a sand texture that sparkles when it catches light, despite not being polished. The niches are an effective way of visually mitigating the watch’s height, which, despite being only 11.7mm thick, would appear greater with slab sides that match the rest of the case. The niches also visually elongate the case’s 46mm length, adding presence where it is beneficial, and reducing it where it isn’t. Overall, a neat trick, and one that looks cool. Another neat trick, and a less noticeable one, is the surface-hardening treatment applied to all the steel elements of the ProSea, including the bracelet and its various components. The coating prevents scratches up to 1,200 Vickers hardness, making the ProSea’s metal surfaces 5-6 times harder than bare steel.
The textured finish of the case’s niches carries over to the inset portions of the bezel’s crenellated grip, where it starkly contrasts the polished outward-projecting sections. The latter is where Circula’s design levity extends a bit beyond my preference, as I would rather see the matte texture from the case utilized for those areas of the bezel. I can’t fault the execution of the finishing, which is precise and flawless, nor the functional execution, as the pronounced grip provides plenty of purchase to spin the 120-click bezel. The bezel uses ball bearings instead of the more common click-spring mechanism, yet Circula has kept the action moderately weighted – I’ve used some ball-bearing actuated bezels that are heavy to operate, which isn’t easy to do with wet hands.
The ceramic bezel insert is similarly scratch resistant as the case, and Circula have utilized fine circular brushing to reduce the material’s shine. The effect evokes the subtle iridescence of aluminum inserts, though it lacks the metal’s warmth. The numerals and graphic design for the hash marks and inverted arrow at zero/sixty are angular and modern, befitting the case, and the dual hues of the bezel markings are functionally and visually beneficial. The electric blue used for the zero/sixty through fifteen positions makes it easy to denote when you are within that critical window for diving, while the greenish yellow used for the remaining markers matches the lume of the minute hand to emphasize elapsed time.
Interesting as the case design is, the ProSea’s dial is the star of the show. As the microbrand market has grown exponentially over the past several years, many brands have focused on dial texture and color to differentiate themselves from competitors. The decision to do so has not always been accompanied by good taste, and the wild dials often feel overbaked, while the watches they sit in feel underdeveloped. Not so with the ProSea – the manta ray skin inspired dial texture blends with the rest of the watch’s design in a way that elevates the entire package. The texture echoes the textured finish of the insets on the case and bezel, and is visually striking, but not flashy. Yes, the ProSea would also look just fine with a flat black dial, but the texture adds complementary intrigue. While I had the most sober of the dial color options, I’ve had a bit of time with the Petrol (a bluish green), and the Blue (it’s blue) dials, and though their hues are brighter, the combination of colors and texture stays far clear of gaudiness.
The visual feast doesn’t end with the dial’s texture, though, as the integration of the dial and rehaut is executed in my favorite style, popularized by one of the greatest dive watches ever made: the Tudor Pelagos. I refer here to the progenitor Pelagos, the rehaut of which has cutouts around each hour marker. Circula wisely incorporated similar in-cuts to the ProSea’s rehaut, which looks simple in execution but no doubt required a lot of effort to measure the different elements so that the final result is properly fit. Adding to the challenge are the raised hour markers, which are applied brushed metal surrounds filled with lume, and nestled within the rehaut’s cutouts with no noticeable gaps to either side. These well-executed choices provide depth to the dial without requiring much physical height, keeping the watch relatively thin without appearing flat.
Thinness is often bandied about as a merit for watches without consideration for its functional benefits – in the ProSea, the short distance between the dial and crystal affords excellent visibility, even at shallow angles. The functional benefit is that one need not look straight down at the watch to read it, which comes in handy during arduous use when optimal positioning may not be possible. There’s also a visually evocative result, as looking from six to twelve at a nearly horizontal viewing angle, combined with the dial texture, calls to mind looking out across a long expanse of desert, the dial surface stretching away for an improbable distance.
A pair of elongated sword hands enables reading of the minutes and hours at those varied angles, with the brushed perimeters matching the frames of the applied hour markers. The lume in the hour hand glows blue to correspond with the hour markers, while the minute hand glows the same green of the bezel markings from sixteen through fifty-nine (recall that the zero through fifteen positions are lumed with a third, blue-green hue). The lumed counterbalance of the blue seconds hand utilizes the same blue shade as the hour hand and markers, while the painted hand’s hue of blue matches the font for the model name on the dial, as well as the zero to fifteen markers on the bezel, when they are not aglow. It’s a bit complex in text, but it works well visually, as does the black date wheel that is color-matched for the black dial, but not for the Petrol and Blue colorways. All the lumed elements are exceptionally bright, as one should expect for a dive watch with professional intentions.
The hands are powered by the Sellita SW 200-1, in elaboré grade form. This higher grade of the venerable Swiss movement offers increased accuracy compared to the base movement (+/-7 sec/day for the elaboré, +/-12 sec/day for the standard version). This grade of SW200-1 can also include a visual upgrade, but if they are present in the ProSea, you won’t notice, as the caseback is solid steel with a manta ray relief.
All ProSea models are available with a quick-release hexad three-link bracelet or a black hybrid rubber and fabric strap. The bracelet comes with a $200 premium ($1,290 with the bracelet, $1,090 on the strap), but it is a well-made addition that I found more comfortable than the strap. Good as the rubber strap is, this is a case where I recommend the bracelet, and you can have at the aftermarket in finding strap alternatives, thanks to the ProSea’s 20mm lug spacing. I make this recommendation even though the bracelet is on the heavier side, weighing in at 86g sized for my 7.5” wrist, making it heavier than the watch at 79g. This might sound off-putting, but in practice, the weight balance keeps the watch head positioned atop your wrist, rather than pendulously swinging about your wrist. No, the ProSea on bracelet isn’t a lightweight, but I found it to be a very comfortable combination in large part because its thinness and flat underside keep its weight close to the wrist.
The bracelet’s clasp has an on-the-fly micro adjustment that is easy to use, and allows you to tighten the bracelet without removing the watch. You’ll have to remove the watch to expand the size, but that’ll give you an opportunity to see the beautiful perlage on the clasp’s arms. The finish struck me as incongruous, at first, with the ProSea’s design, but it is in line with the watch’s other flourishes, namely the textured niches of the case flank and polished flanges on the bezel grip. Taken together, there’s a whimsical oddity to these flourishes that is charming.
One of the aspects I appreciate most about smaller brands is their willingness to be creative with their design choices, and the Circula ProSea is an example of how to do so with good taste. It has quirks of polish and perlage that won’t be to everyone’s taste, but they aren’t unconsidered as part of the overall design. Similar for the dial texture, which is an homage to where the watch wants to go – beneath the waves where the manta rays swim. These aren’t gimmicks to garner clicks, but design choices that represent the brand’s playful, yet purposeful, ethos.
The Circula ProSea is available directly through the brand’s website. You can also see Circula at District Time 2026.
