Why the Seiko SKX became the ubiquitous affordable diver, and the gap left in its wake

Borna Bošnjak

What constitutes a truly iconic watch? Does it need to accompany someone conquering depths and heights never reached, or present such a revolutionary design that it creates an all-new category, with many following suit? Those reasons are all valid. But sometimes, you also just need a bit of luck, and a whole bunch of adoring fans. Responsible for sending oodles of curious, potential enthusiasts spiralling into a life of addicted aficionados, we’re talking about the Seiko SKX, of course. Stemming from a rich lineage of high-tech dive watches (and also helped by Seiko being well-respected across its offering), but eventually carving its own niche as the watch every budding (or otherwise) watch enthusiast needs. It was omnipresent, needing little argument to convince buyers other than “well, it’s an SKX”, beating out more capable, more modern, and at times, more affordable offerings. The how and why is what we’ll figure out today.

From high-tech tools to daily champions

The SKX followed a three decade-long history of Seiko dive watches, which started with the brand’s technological advancement push for the 1964 Tokyo Olympics. Chosen as the official timekeepers, the Japanese industrial powerhouse produced everything from swimming pool touch pads to the world’s first electronic mini printer that would be commercialised four years later. But it’s the watches that take the top spot of the podium.

Apart from launching a worldtimer and two legendary chronographs that deserve a story of their own, the brand was also working on the follow-up to the Seiko Sportsmatic SilverWave – a 50 (or 30, if you got the cheaper one) metre water-resistant model. Just a year later, the legendary 62MAS came out, and kickstarted a chain reaction that would see Seiko introduce high-beat movements, monobloc cases, and helium-proof titanium (and later, ceramic) shroud construction.

But if you know the SKX, you’ll know this was no ultra high-end diver with a mighty movement. It did all it needed to do, and nothing more, and all for a fair price. As such, we also need to talk about the 1960s and Seiko 6105 – or the Willard, to its friends – which sat alongside the flagship Tuna as the value prop for the everyday enthusiast. The guarded, 4 o’clock crown case would mould into the what we recognise as the modern Turtle throughout the ’70s. As an aside, the following paragraph comes with a bit of a warning – many reference numbers will be referred to. Apologies.

Apart from giving us bell bottoms and glam rock, the ’70s also brought quartz watches into the fray, and as its progenitors, Seiko used it extensively, including in their dive watches. With the advent of the quartz-powered 7548 in 1978 (which was ingeniously based on the automatic movement of the 6309 but adapted for quartz power delivery), we’d finally see the recognisable SKX shape fully take form. Curiously, the 42mm 7548 was joined by the 38mm 6548 in the same year, but with the smaller watch sporting a better quartz movement. This would make the full-size, follow-up 7c43 Professional an evolution of the smaller 6548 rather than the 7548.

As 1988 rolled around, the now-famous SKX case would see its very first automatic movement, as Seiko discontinued the Suwa 6309 and replaced it with the Daini 7000-series calibres. To go along with the naming scheme, the Japanese brand introduced the 7002 diver. Though it would later bump its water-resistance to 200 metres (becoming the first non-Prospex model to do so), the 7002 was a further step down in the range, as Seiko still prioritised quartz at the time. Despite the movements still being excellent timekeepers with improvements over the 6xxx, the 7002 wasn’t exactly favoured for its Marmite dials and lacklustre lume.

And finally, we’ve made it to 1996, and the SKX’s introduction. It was the spiritual successor of the 7002, but improved upon it with ISO diver’s certification and upgraded 7s26 movement. That might be an odd thing to say, especially being someone who has harped on about the 7s26 being outdated, but when these watches were new, they impressed with their construction and robustness. It starts with a 38mm and 42.5mm cases, and a whopping 14 models in its first year.

What made the SKX great

The one thing that is consistent with all of Seiko’s dive watches, Prospex or otherwise, is that they were actual tools, actually built for doing actual things. The SKX became the pinnacle of this ideology, despite its waning technological advantage as the years went by with no updates. But it didn’t matter. Seiko built its reputation in the 30 years before releasing the SKX, and as the hero of our story became more widespread and more affordable, it only became more of a cult classic.

Starting with the dial, I’ve heard it described as a design only a mother could love. Why I don’t exactly share the sentiment about it being such an ugly duckling, I do concur that the SKX wasn’t made to be pretty. It was made to be legible many metres under the surface, where light is at a premium. That successful, functional design makes it attractive enough for me, kind of like a Volvo 240. It replaced the 7002’s square indices for circles, with the cardinal markings denoted by elongated ovals and a triangle at 12. But the actual, significant upgrade over its predecessor was the use of LumiBrite, Seiko’s proprietary mix, whose brightness has become the stuff of legend.

Then, of course, there was the 7s26 movement. It’ll long hail as one of the most underrated calibres around given how much it was (somewhat rightly) panned for being used even 30 years after its introduction. Regardless, it remains incredibly durable. Mine, for example, has been happily ticking along for the best part of a decade now, though I’m sure there are also some other there that haven’t been serviced since the ’90s. It features Diashock protection, 21 jewels, and a slow, 3Hz beat rate, but thanks to their lightweight gear trains, they’re able to produce consistently high amplitude without overworking the movement. Famously, the movement doesn’t have hacking nor hand-winding. I’m perfectly content without the former, but even though some say that Seiko’s Magic Lever winding system renders the latter unnecessary, it’d still be nice to have.

And if you need any proof of just how good this movement is, Seiko still uses variants of it today. The 4R and 6R movements are upgraded versions of the base 7s26 calibre, with more modern mainsprings to provide a longer and more stable power delivery – and with hacking and hand-winding, of course.

The real catch though was how affordable the SKX became over the years, because what’s the point of having a great set of specs that nobody can afford? The most popular variants, those being the SKX007 and SKX009, could regularly be found for under US$200 – you’ll pay similar prices for some Swatches these days. This made it an unreal value proposition, and made the hobby of mechanical watch collection accessible to just about anyone. And here’s the thing about Seiko. It’s a truly vertically integrated company, so everything is “in-house”, from their cases to their movements, even down to their own proprietary lubricants and quartz crystals. While Seiko has certainly produced a metric tonne of quartz watches (unsurprisingly, since their Astron was the first in 1969), I’d venture to say that the brand has done more to keep interest in mechanical watches alive than most companies during that dark period when it seemed their days were numbered.

The SKX legacy

Nowadays, the SKX as such is no more, replaced by the less capable Seiko 5 SKX Style and its many variations. We’ve even seen homages to the 7002 via the 5KX, though they’ve all featured 100 metres of water-resistance and no screw-down crown. That said, though, they do feature the 4R36 movement which is an upgrade over the 7s26, despite sharing base construction. Though met with lots of initial criticism, special editions and expansions of the line like a 38mm colourful quartet, even the most die-hard fans of the SKX seem to have softened up a little, until you check out the darkest depths of the Seiko forums, that is. But the one thing that the 5KX has over the SKX at the moment is sensible pricing. Unless nostalgia is really rocking you, making an argument for spending nearly five figures on a NOS SKX009J is becoming harder and harder…

The SKX’s legacy, however, is strong even outside of watchmaking circles. Queen guitarist and absolute legend Brian May has long been a Seiko diver fan, and now has his own model, based on the look of his famous Red Special guitar that he built at home with his father.

If you’ve been doing a bit of movie watch spotting for an SKX, its most famous appearance is likely in the survival thriller All Is Lost. Aside from Robert Redford basically not speaking throughout the entire film, attempting to survive the gruelling Indian Ocean, he notably wears the SKX009 on a blue NATO-style strap.

There was more to the SKX than you’d think

Offering such value, it’s little wonder that the SKX became the point of entry for so many in our hobby. Just about every collector I know has owned an SKX at some point. Whenever someone mentions the SKX, you likely think about the asymmetrically cased, 42mm watch and its printed dial. Whether you imagine a Pepsi or a black reference wholly depends on the one you lusted for, though. There is much more to the SKX line of references than those two pieces, going as far as completely different case designs and dial configurations. You’ll find orange dials, yellow dials, and later, different case styles (even titanium ones) under the SKX moniker. Other than the main line, the most popular spin-off series were the Monsters, with their bulbous bezels and teeth-like dials. If the 4 o’clock crown wasn’t quite your jam, you could go with the SKX031, which in many ways resembled the Rolex Submariner and became an in-the-know Seiko community darling.

Before diving into some of the most significant, rare, and curious models spawned under the SKX reference, a quick word on one important aspect of the reference number itself. Something you’ll run across when diving into the Seiko pool is the question of the Japan-made “J” models versus the “K” models, which are manufactured at Seiko facilities in Malaysia, Singapore, or Hong Kong. The J versions command a premium over the K models, and acolytes insist they’re of higher quality, but having handled dozens of different models over the years, the difference between them is mostly cosmetic (with slight dial variations, i.e. “Made in Japan”), and largely semantic. Decide for yourself if those differences are worth the extra cost, and don’t @ me, fanatics.

We can’t start without talking about the most recognisable model of the series, which is the Pepsi-bezelled SKX009. Available in both J and K variants, it solidified its status as a downright icon with its bi-colour bezel and powder blue matte dial. It’s not rare, though collectors will sometimes prefer models with English-Japanese day wheels versus others. If you happened to buy one in North America, though, you might know it as the SKX175. The two were virtually identical, with the SKX175 being the North American market version of the SKX009, with one tiny difference, its dial reading “MALAYSIA” below the 6 o’clock marker. Alternatively, and being one of the rarest Seiko SKX variants anywhere, are the 175s with “SINGAPORE” on the dials instead.

It’s the watch that got me interested in Seiko, and the very first one I ever bought has been with me for years now, looking pretty much perfect despite being subjected to a beating at least once a month. I’m just waiting for the red on that bezel to turn fuchsia, and I may or may not have forgotten it on a sunny window sill once or twice. Any day now…

Similarly to the 6548 and 7548, the SKX line also had a mid-size and full-size option. The latter is by far the more common one, with some of the rarest SKXs made in the mid-size, 37mm size. The SKX013 is by far the most common of all the variants, and was often recommended as the smaller foil to the larger, ubiquitous SKX007. If you want a smaller Pepsi, you’ll have a much harder time finding one, as the SKX015 is much less common, and especially so in all-original condition – something it shares with many of these old Seiko divers. Undoubtedly the rarest of all three is the orange SKX017, allegedly produced for three short years after its 1996 introduction, and potentially only sold in the Philippines.

Though I’m yet to come across one in person, a model I’ve been hunting for some time now is a titanium SKX. First introduced in 1999, the 42mm cases came with two bezel styles, and either 7002-style or SKX-style dials in black, silver, or orange. In many ways, I see these as the ultimate SKX models, with more advanced case materials and applied bezel indices. The SKX403 is the one I really want, but finding one with an original bracelet has been very difficult.

Finally, while they’re not true SKXs in anything other than reference number, I’ll say these Monsters technically qualify. Whether you went with the SKX779 Black Monster or SKX781 Orange Monster, I don’t really need to explain why these watches were nicknamed the way they were. The aggressive, razor-backed bezel is supremely grippy, and the cutout case design recalls the Seiko Tuna, but in a more manageable size. And if you thought the regular SKX lume is great, wait ’till you spot a Monster in the dark…