Seagull Ocean Series Pro 300m Watch Review

I’ve been looking forward to this one for quite a while. This latest model of Sea-Gull Ocean Series Pro isn’t just another diver — it’s a fully in-house original build, yes including the movement, with serious engineering behind it, and in my opinion, it is one of the most compelling original divers coming out of China right now.

It improves on the previous model in all the right places, and the previous model, which I reviewed recently, was already pretty good. That said, there are a few details that you won’t notice from product photos alone, most of them are really positive, and so I'm not sure why Seagull is being modest about them. However, I still have a question or possibly two about some design decisions here. So, let’s take a closer look.

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Design

Now when it comes to design, this is very clearly an evolution of the previous Ocean Series — but Sea-Gull has definitely stepped things up. So, visually, this one feels more modern and more resolved from pretty much every angle. The proportions are tighter, the dial feels more involved, and overall it’s just a more interesting watch to look at on the wrist. And, even though it still has a bit of girth and carries some real heft, the wearability is actually very good — and a lot of that comes down to those nicely curved lugs, which pull the case down and help it sit far more comfortably than you might expect.

One of the biggest visual upgrades is the bezel, and we’ll get into the details shortly — but yes, it is fully lumed, and I think we have a sapphire insert here, which we will definitely check just now. Sea-Gull is usually quite conservative with materials and design choices, so seeing them go all-in like this is genuinely refreshing.

The dial itself is also more engaging than before. The date magnifier aka cyclop has gone and the actual date moved down to 6. The overall still layout remains clean and purposeful, but there’s a stronger sense of depth and refinement overall. And then there’s the lume — which honestly surprised me. Not only do we have a fully lumed bezel, but the dial lume is very good too… definitely better than I expected going in.

Now, In terms of proportions, I also really like where this lands. It’s listed as a 40mm watch, but visually it sits right in that classic diver sweet spot. The bezel measures around 40.6mm, which is actually very close to where something like a Submariner lands visually on the wrist, actually while the latest Rolex diver is listed as 41mm it is in fact about 40.6 mm in diameter — so the footprint of this Sea-Gull feels very familiar and very wearable.

As for colorways, I personally think this black version looks fantastic, though there are several others available. Just keep in mind that some of the alternative versions jump up to 44mm, which will wear quite differently.

And we do have to address the price, because that’s another big shift compared to the previous model. That earlier generation sat somewhere around just over $200 mark before tax. Now, this one, depending on timing and discounts, lands closer to the $410 before tax range — so definitely not a budget diver.

That said, when you factor in what Sea-Gull brings to the table here — including the in-house movement — it starts to make a lot more sense. In today’s market, where brands like San Martin and Sugess comfortably sit in that same price bracket, and where Swiss or Japanese alternatives quickly climb well beyond that mark, this Sea-Gull feels like a very compelling package overall. But we’ll circle back to value a bit later in this video.

Dimensions

Now in terms of dimensions, this one sits right in that classic diver territory. The case measures 40.6 millimeters across when taken from the bezel, which ever so slightly overhangs the case. Lug width is 20 millimeters, so plenty of flexibility when it comes to strap options. Thickness comes in at just over 13 millimeters. Now, that’s obviously not what we’d call slim — but we do have to keep it in perspective. This is a 300-meter diver, and within that category, the profile is actually very reasonable.

Now, lug-to-lug is nicely contained at 47.5 millimeters, and thanks to the curved lugs and the way the inverted end links, it wears noticeably more compact than the numbers might suggest.

As for weight — this is definitely a proper tool watch. On the bracelet, it comes in at around 180 grams, so yes, it has real presence on the wrist.

Case

Now moving on to the case — and honestly, even though the dial probably grabs most of the attention at first glance, the case here is a bit of an unsung hero. It’s very well executed and, to my eye, actually more interesting than the previous generation.

There’s a lot going on in terms of shaping. The mid-case has those nicely sculpted shoulders that flow into smoothly integrated crown guards, and the lugs curve down beautifully toward the wrist. It’s quite a complex case in terms of geometry, and Sea-Gull has done a great job with both the carving and the finishing.

Up top, we’ve got clean brushing across the lugs and case surfaces, while a crisp, high-polished chamfer runs along the edges, catching the light nicely and adding a bit of refinement to what is otherwise a serious tool-watch design. The brushing continues along the flanks as well, and overall the finishing quality here feels very solid.

Over on the right-hand side, the crown setup is equally well executed. The crown itself features a gear-style knurling that offers excellent grip, and it’s signed with the Sea-Gull logo. As expected on a 300-meter diver, it’s screw-down — and I have to say, operation is excellent. The threading feels smooth and robust, and there’s a reassuring sense of mechanical refinement when engaging and tightening this crown.

Flip the watch over, and we’ve got a polished back of the case with a screw-on caseback which features a bold embossed Sea-Gull star medallion at the center with a not so subtle reminder that they have been around since 1955and this piece is capable of withstanding 300m of water resistance. Surrounding it are engraved specifications, model details, and an individual serial number — a nice reminder that this is a full production piece from a major manufacturer rather than a small-batch microbrand.

Crystal

Up top, we’ve got a perfectly flat sapphire crystal, and it’s very nicely integrated into the overall design. It sits almost flush with the bezel, which not only keeps the profile clean but also gives the watch head a very cohesive, purposeful look.

Execution here is excellent. The crystal is well seated, offers strong scratch resistance for the top of the watch, and the anti-reflective coating works very well — reflections are nicely controlled, and legibility stays strong even in brighter conditions.

As I mentioned earlier, Sea-Gull also decided to remove the cyclops on this version. Personally, I don’t mind that move at all. The date window is already quite clear and easy to read, and without the magnifier the dial just looks cleaner, more balanced, and a bit more refined overall.

Dial & Lume

Now turning to the dial — and this is another area where Sea-Gull really got it right. First of all, I genuinely like the design here. It feels distinctive and very much its own thing, rather than borrowing heavily from anyone else. In fact, in terms of execution and overall design quality, I’d comfortably put this up there with some of the better-known diver dials from brands like Seiko, Rolex, or Omega. It’s clean, confident, and very well resolved.

Starting with the dial background. We’ve got a nice but not overly pronounced gradient fumé effect which is combined with a subtle sunburst pattern that adds depth without becoming distracting. And it transitions very smoothly into the shallow rehaut, where the minute markings are printed.

The applied indices are another highlight. They feel unique in their shape and proportion, with strong lume fill and clean finishing throughout. The 12 o’clock marker has its own distinct presence, and combined with the date at 6 o’clock, the dial stays very well balanced overall.

Speaking of the lower half, we also get the applied star above the text — a signature detail within Sea-Gull’s Ocean Series divers — and I think it adds just the right amount of character. Typography across the dial is also very well judged: restrained, legible, and nicely spaced with no clutter.

The handset works equally well. It’s slightly unusual, with a semi-skeletonized sword-style design that feels appropriate for a diver and matches the rest of the dial nicely. Proportions are good, legibility is strong, and everything feels cohesive.

Now when it comes to lume, performance is very solid. As you’ll see in the 15-minute lume test, it’s not over-the-top bright, but it absolutely holds its own. In real-world use — evenings, low light, nighttime checks — it’s been perfectly practical, so no complaints here.

Bracelet and Clasp

Now moving on to the bracelet — and overall, this is a very nicely executed piece of the package.

It follows a familiar oyster-style layout but still manages to feel like its own thing. Construction is solid 316L stainless steel, matching the case, and the overall build feels appropriately substantial for a 300-meter diver like this. The links are quite chunky, which works really well visually with the watch head and gives the whole piece a cohesive, tool-watch presence.

One detail I particularly like is the shaping of the links. So the end links are slightly recessed, which you might already know I’m a fan of, and the center parts of the rest of the bracelet links sit just a touch higher than the outer sections. And combined with the finishing approach — brushed center links and high-polished outer portions — it’s actually quite clever. Because in real-world use, the brushed areas tend to pick up the unavoidable scratches first, while the polished edges stay looking cleaner for longer. Honestly, I wish more brands approached bracelet finishing this way.

So, finishing overall is strong: clean brushing, crisp transitions, and very good comfort on the wrist. The bracelet is fluid, well articulated, and balances the weight of the watch head very well. Link connections are fine with pins, which is perfectly fine here — screws possibly would’ve been nice at a higher price point, but functionally there’s no issue.

Now, moving to the clasp — and this is probably the least exciting part of the watch. It’s essentially carried over from the previous generation. Build quality is solid, with a milled inner mechanism, double push-button release, and three micro-adjust positions. It’s also signed, which is a nice touch.

That said, the overall design is fairly basic for this price category. It works perfectly well, feels secure, and does the job — but considering everything else Sea-Gull has done with this watch, a slightly more refined clasp would’ve rounded things off nicely.

Still, in daily wear, the bracelet and clasp combination works extremely well. The chunkier bracelet really balances the watch head, and overall comfort is excellent.

Verdict

So, circling back to the price at around $400, if we’re being realistic, the closest mainstream comparison probably lands somewhere around entry-level Seiko divers like the 5KX line, which aren't exactly divers to start with and definitely don’t give you the same overall package. You’re not getting sapphire across the board, you’re not getting this level of finishing, you’re not getting a screw-down crown with 300 meters of water resistance — and, Seiko’s entry level movement doesn't match the performance of Sea-Gull calibre inside of this diver.

If you start looking higher up the Seiko ladder — into the $700 to $1,000 range — that’s where things become more comparable in terms of presence and overall feel. And once you step into Swiss territory, the equation shifts even further.

What Sea-Gull has done here is genuinely impressive. You’re getting an original design, a strong in-house caliber, serious diver specs, and a watch that visually can stand shoulder to shoulder with some very established names in the category. It’s not perfect. The bezel grip — which, as we discussed, carries over from the previous generation — could definitely be improved, and the clasp feels a bit basic relative to the rest of the watch. But outside of those points, the watch head itself is excellent. And personally, after spending time with it, I’m genuinely impressed.

Bezel

Now turning to the bezel — and this is easily one of the more interesting updates on this watch. First things first, while I have the diamond tester out and warmed up, let’s check the insert — and yes… it is sapphire. That’s genuinely impressive, especially from a brand like Sea-Gull that usually leans conservative. And more broadly, between the sapphire insert and the fully lumed bezel execution, it’s clear they’re very much in step with the modern dive bezel trends.

Now, the layout itself is exactly what you’d want from a proper diver. Markings are clean and functional, the lumed triangle at 12 is integrated neatly into the insert rather than protruding, and everything feels visually well balanced. There’s also a small decorative detail inside the triangle — not entirely sure what the reference is, but aesthetically it works.

So, yes, we get a fully lumed bezel here, which isn’t just about looks — it’s genuinely practical. I’ll show it properly in my lume test just now, but performance is strong and very usable in low-light situations.

In terms of operation, alignment on my sample is spot-on, tolerances are very good, and overall the action feels solid and consistent. I’d say it is even slightly improved over the previous generation — not class-leading at this price point, but still decent and perfectly usable.

Now, one criticism — and this is actually something carried over from the previous model — is the bezel grip. The edge is fully polished, which looks nice visually but in practice does make it noticeably slippery in use. So to enjoy that bezel action it does require a stronger than normal squeeze. If Sea-Gull had introduced some kind of brushing on this grip, even partially, it would’ve made a big difference. But, as it stands, you just need a slightly firmer grip to operate it.

So the action is kinda of okeyish, although, interestingly, after a couple of weeks of turning this bezel it did start to feel a bit more natural and enjoyable.

Movement

Inside, we’ve got the Sea-Gull ST2130 — a fully in-house automatic movement and one that’s very well regarded among enthusiasts. In terms of architecture, the ST2130 is based on the Swiss ETA 2824-2 layout, which puts it in the same family as movements like the Swiss Sellita SW200 and the PT5000 from Hong Kong Precision Technologies.

Sea-Gull has been producing this caliber for well over a decade now, and over that time it’s built a strong reputation for reliability. It runs at 28,800 vibrations per hour, offers hacking and hand-winding, and comes with a stated power reserve of around 42 hours. It’s robust, well understood, easy to regulate, and reinforces the whole fully in-house positioning Sea-Gull is clearly leaning into with this diver.