Borealis Porto Covo 300m Diver Watch Review

Microbrands are popping up everywhere right now. And let’s be honest — a lot of them play it safe. Familiar cases, familiar dials, familiar movements.But every now and then, one comes along that actually tries to do something different.This is Borealis — seems like a proper microbrand, not some marketing shell — and this Porto Covo diver well it ticks some very interesting boxes. A genuinely original and refreshing design in a space where originality is getting harder and harder to find. We also get a premium automatic movement instead of the usual entry-level default. And full, serious diver specs to back it up. Oh — and it looks really good. And the price? Surprisingly reasonable for what’s on offer. So what exactly are we dealing with here? Well we have it here - Let’s take a closer look.

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Design

So looking at design and the headline feature here is that floating index dial. It’s unusual. It’s dimensional. The hour markers appear suspended above the dial surface, creating this layered, three-dimensional effect that shifts depending on the viewing angle. I genuinely can’t recall many other brands executing something quite like this in a dive watch format.

And yet — despite that unconventional touch — the dial remains very classic and very well balanced. Large applied hour markers, strong symmetry, clean typography, and excellent legibility. Everything you’d expect from a serious modern diver is here: fully lumed hour markers, clear handset, and a bezel layout that’s purposeful and easy to read. And just a heads up — lume performance on this one is not to be underestimated.

Now, the case design deserves some credit too. Yes, it’s very much tool like — but remember, we’re dealing with 300 meters of water resistance here, with a screw-down crown, and all the hallmarks of a proper dive watch build. This piece actually has the structural backbone and all the prerequisites to pass formal dive iso certification if the brand wanted to go that route.

What I particularly like is how the crown is integrated. It sits at four o’clock, which already improves wrist comfort. But Borealis didn’t just shift the position — they sculpted the case around it. The crown is slightly flatter, a little more tucked in, protected by well-shaped crown guards, yet it is still easy to engage.

Finishing is also clean and contemporary — pretty much sand blasted surfaces all around giving it that utilitarian dive aesthetic. The bezel here is fully lumed. Now, the bezel markings don’t glow quite as intensely as the dial markers, but the lume pip at twelve is lume well enough and legibility remains strong.

The bracelet is also very well executed — solid, properly integrated, and yes, it features on-the-fly adjustment, which we’ll look at more closely in the bracelet section.

As for the name — Porto Covo is actually a coastal village in Portugal, and Borealis leans into that maritime identity. According to the brand, the idea here is to create watches that combine functional dive capability with distinctive design — and that philosophy definitely shows in this piece.

And finally, if this particular colorway feels a bit conservative for you — there are several dial options available within the Porto Covo line. Different colors, slightly different textures, but all carrying that same floating index concept. So you’ve got room to choose something that fits your taste.

So yes — from a design standpoint, this is not just another diver. It feels fresh, but still grounded. Now, let’s talk about what’s powering it, because that’s another area where Borealis made some very deliberate choices.

Dimensions

Now, when it comes to dimensions — no surprises here, and that’s a good thing. This is a very well-contained set of numbers.

Case diameter: 40mm

Lug-to-lug (case only): 42.5mm

Case Thickness: is 12.6mm

Lug width: 20mm

And the weight on the supplied bracelet is 150g.

Now, on paper, that 42.5mm lug-to-lug sounds beautifully compact — and technically, that’s correct if you’re measuring the case. However, this watch uses kinda protruding inverted end links. They do curve down quite aggressively, which helps with comfort, but they have almost no articulation. So in practical terms, the effective span from end link to end link measures just over 52 millimeters. Now, that’s still very reasonable and is important in a context. The 40mm case keeps this diver in that sweet spot for most wrist sizes, while that slightly wider effective footprint gives it a bit more wrist presence, especially on larger wrists.

Case

The case design here is very straightforward — and I mean that as a compliment.

It’s utilitarian, tool-like, and purposeful. There aren’t any exaggerated chamfers or flashy polishing tricks. Instead, Borealis went with a predominantly sandblasted finish across the stainless steel case, which reinforces that proper dive-watch character.

There are subtle bevels and soft transitions along the edges, but they’re understated. Nothing here feels decorative for the sake of it. It’s clean, cohesive, and original without trying too hard.

Now, we already touched on the crown placement, but it’s worth repeating — the screw-down crown sits at four o’clock, and the case is sculpted really nicely around it. It doesn’t protrude awkwardly like on some designs, yet it’s still large enough for easy engagement. The crown guards are well integrated, protective without being bulky. It’s a very deliberate and well-balanced execution.

Flip the watch over, and we’ve got a solid screw-down caseback with a tastefully engraved maritime motif with a mermaid at the center. And another interesting detail - around the perimeter, the notches used for opening the caseback are arranged and finished in a way that almost resembles a ship’s wheel, which ties nicely into the coastal, nautical theme of the Porto Covo name. Whether that’s fully intentional or not, I'm not sure, but it works.

And of course, structurally speaking, this case delivers 300 meters of water resistance. Combined with the screw-down crown and the screw-on case back, this absolutely makes it safe for swimming and even some recreational diving.

Crystal

Up top, we’ve got a flat sapphire crystal.

Nothing dramatic here — just a straightforward, modern execution. It sits cleanly against the bezel, keeps the profile controlled, and does exactly what it’s supposed to do.

The anti-reflective coating is effective, reflections are well managed, and legibility remains strong even in brighter light. So yes, no gimmicks, no distortion, no complaints.

Dial & Lume

Now, the dial here is really well balanced. Despite the floating index architecture — which is the visual headline here — nothing feels chaotic or overdesigned. It’s controlled, legible, and properly thought through.

The background carries a subtle sunburst finish that plays nicely with the light. The minute track is printed on the rehaut, which keeps the dial surface clean and adds a nice sense of framing.

And even in this silver-on-silver kinda off configuration — silver hands against a silver-toned dial — legibility remains strong. The faceted, sword-style hour and minute hands catch the light differently from the dial surface, creating enough contrast to avoid washout. It’s actually quite well judged.

The date window sits at six o’clock, maintaining that symmetry. And importantly, Borealis kept a portion of the six o’clock marker visible and lumed, so we don’t lose the structural balance of the dial — or nighttime functionality. Now, speaking of lume… As promised - here is my 15 minute lume test and this diver does not disappoint. All hour markers are fully lumed, the handset is also generously covered with lume, and performance is strong. I won’t say it outright crushes Seiko’s best divers, but it absolutely holds its own. Bright, evenly applied, and long-lasting. We also get lume on the bezel markings and overall, nighttime legibility here is very impressive.

Bracelet and Clasp

Now, the bracelet here is actually very well executed. Even though we’ve got 20mm lugs, the end links flare out slightly to meet the case more seamlessly. Measured across the end links, we’re looking at roughly 23.8mm, which gives the watch a broader, more integrated stance at the top. It transitions into the case nicely and avoids that narrow, pinched look you sometimes get with straight 20mm bracelets.

From there, we’ve got a proper taper down to 18mm at the clasp, which keeps things balanced and comfortable.

The bracelet itself is an H-link design, fully stainless steel, with solid links throughout. It’s entirely sandblasted to match the case, maintaining that cohesive tool-watch aesthetic. Articulation between the links is very good — smooth, flexible, and nicely finished.

Now, here’s a detail I really appreciate. The links are secured with screws — but not the most common type. Borealis uses screws where the threading is done on the screw head side rather than relying on a more conventional approach of threading on the opposite end. This is actually my preferred setup, and something we’ve seen on some higher-end pieces as well. What that does is makes the screw less likely to get undone and reduces the risk of over-tightening the link. So it is generally a more robust, more confidence-inspiring system compared to the more conventional designs where the thread sits on the opposite side.

It’s a small technical detail — but it’s the kind of detail that tells you the bracelet definitely wasn’t an afterthought.

Now, moving to the clasp — we’ve got a fully milled, double-pusher clasp, also very well executed. Branding is subtle and tastefully done. And the clasp also features sandblasted finish in line with the rest of the watch.

And yes — this one has an on-the-fly adjustment. It’s a robust, practical system that works exactly as it should. Smooth to operate, secure in position, and importantly, it keeps the outside of the clasp clean. There are no visible external screws or other elements disrupting the design. So, yes, nothing to complain about here.

Verdict

So, let’s talk about price. This one comes in at £304 or around $395 US, before any discounts.

And for what we’re getting here — well that feels very competitive. You’ve got a genuinely original design in a segment that often leans heavily on familiarity. You’ve got a premium Miyota 9 thousand series movement, 300 meters of water resistance, strong lume, proper bracelet construction, and on-the-fly micro-adjustment — which is still something not every microbrand includes at this level.

So, it checks the functional boxes and it checks the quality boxes too. And importantly, it brings something visually fresh to the table. Are there any major points of contention? Not really. The bezel isn’t class-leading, but it’s solid. Everything else feels well thought out and competently executed. In the current microbrand landscape, this feels properly positioned and quite fairly priced.

Bezel

Now, moving on to the bezel. We’ve got a 120-click unidirectional bezel with a ceramic insert — exactly what you’d expect at this level. The insert itself is cleanly executed, it is a grey slightly brushed ceramic with crisp numerals, clear minute markings and of course with a lume pip inside the triangle at 12.

The bezel grip follows the same aesthetic language as the rest of the watch. It’s sandblasted, slightly unconventional in shape, and integrates nicely into the overall tool-like design. It’s not aggressively sharp, but it’s absolutely functional and easy to operate. In terms of bezel action — I’d call it good, but not class-leading.

There is a slight bit of back play. Nothing major, nothing that compromises usability, but it’s there. Resistance is solid and consistent, and alignment on this sample is good.

One interesting thing — straight out of the box, the bezel felt quite tight. But after spending some time with it, it’s loosened up slightly and now feels kinda just right. So in this case, use seems to have improved the action rather than degraded it. So overall — solid, reliable, maybe not exceptional, but absolutely competent and in line with the rest of the watch.

Movement

Now, powering this particular Porto Covo is the Miyota 9015 — part of Miyota’s premium 9 thousand series line. That means 28,800 vibrations per hour smooth sweep seconds hand, proven reliability, and a movement that’s widely respected for its consistency and long-term durability.

In this price segment, the 9015 is arguably one of the best options available in terms of performance and reputation. It’s not entry-level and definitely not a cost-cutting choice.

And here’s another detail I appreciate — Borealis doesn’t take shortcuts. If you go for a no-date version of this watch, you get the no-date variant of the movement, the Miyota 9039. That means no ghost crown position, no lazy compromises. It’s the kind of decision that shows attention to detail.

And when we talk about price later, the fact that Borealis is offering a premium 9 thousands series movement at this level makes the overall package even more compelling — especially when you compare it to what else is floating around in this segment. So yes — movement choice here is absolutely commendable.