Before getting on with the comparison, a short bit on the country of origin of each: the orange 5KX used for this article is a Seiko SBSA009; this entails that the model is made in Japan (as the small text on the dial indicates.) This watch is also available in an international market version as the reference SRPD59.
The SKX011 was also available as a made-in-Japan and an international-market version. The two references were SKX011J and SKX011K, respectively.
With both the newer Seiko 5 Sports and the older SKX, the differences between the made-in-Japan (JDM) and international-market versions are merely cosmetic and rather minimal. The country of origin did not affect the mechanical performance nor the overall quality of the watches. However, the Japanese models generally command a premium on the second-hand market.
SKX011 vs 5KX Case Comparison
Seeing as how the 5KX line of watches took much inspiration from the preceding SKX line of watches, it should come as no surprise that the cases of these two divers are almost identical, at least on the surface.
Each boasts the same 42.5mm diameter, 13.4mm case thickness, 46mm lug-to-lug measure, and 22mm strap size (between the lugs).
The differences between the 5KX and the SKX011 begin at the lugs; the SRPD59 has lug holes whereas the SKX does not. These do not affect the structural integrity of the watch, however, they do make it very easy to change the strap on the watch. Most critically, they help prevent unsightly scratches on the underside of the lugs.
SRPD59 / SBSA009 (Made in Japan)
On the other hand, the Orange Boy possesses a significant advantage – its screw-down crown. This allows the watch to attain a 200m water resistance rating that doubles the SRPD59’s 100m rating resulting from a non-screw-down crown.
On the underside of the case, the 5KX wins out with its see-through caseback. Perhaps a vain detail, I’ve yet to encounter a watch collector who isn’t mesmerized by the mechanical intricacies of their watches. Being able to admire this from up close at any time is a critical benefit. It’s also worth noting that the 4R36 movement inside all modern 5 Sports watches has an attractive bit of finishing on its plates and bridges.
Diver’s Bezel Details
The design and execution of the two bezels are largely the same.
The bezels are unidirectional with a grooved outer edge for improved grip. They also both possess the gold-on-black diver’s insert theme, though the SKX has full 60-minute calibrations. Finally, the latter also has a luminous pip that would, in theory, permit the SKX to attain a professional diver’s watch certification.
The crystals used on both the 5KX orange and the SKX011 are Seiko Hardlex, a proprietary material that is modestly resistant to scratches and is shatterproof.
Seiko Orange Dial Diver Comparison
Though both dials are orange-toned, it is in the dial department that these two Seiko divers differ the most.
For one, the SKX011 “Orange Boy” boasts a bright orange dial with a flat texture and lume plots that are applied directly to the dial. The SRPD59 instead has a lustrous sunray texture with applied hour indices that has luminous fills.
Past that, both have black minute markings, gold-toned center hands, and the day-date aperture at 3 o’clock.
There are some non-negligible differences regarding the Seiko marquee at 12 and the other text present above the 6 o’clock index. I think these differences further differentiate the SKX as a more utilitarian style and the SRPD59 as a gleaming and dressier watch.
Steel Bracelet vs. Rubber Strap
The Seiko 5 Sports SRPD59/SBSA009 is a clear winner in the OEM band department. That’s because it’s equipment with a sturdy 3-link bracelet with folding clasp.
On the other hand, the SKX011 was sold on a black rubber strap that I always found to be rather stiff and uncomfortable to wear for extended periods of time. Many collectors treasure the look of the Seiko “Wave” rubber strap and, while I did warm up to it the longer I wore it, I definitely do not prefer it over the bracelet.
Of course, one can always change the strap on the SKX011 to make it more pleasant to wear, but if we’re doing an apples-to-apples OEM comparison, the steel bracelet wins “every day of the week and twice on Sunday.”
Seiko 4R36 vs. 7S26 Movement
As you may have found in the direct comparison near the top of this article, the movement is another area where there is a direct disparity between the two models. And while both are self-winding movements widely regarded as reliable and durable, there are some key differences.
Here, the SKX011 is a victim of its age as it’s equipped with a Seiko 7S26, a movement first released in the ’90s. The power reserve is standard at around 40 hours but it does not count hand-winding nor a hacking seconds function as advantages.
Alternatively, the 4R36 has a marginally improved 41-hour power reserve but it is further enhanced by the two features the SKX lacks and which are standard in modern automatic movements: hand-winding and hacking seconds (stop seconds). The 4R36 also has improved accuracy though neither watch is extremely accurate and both can be regulated by a watchmaker to improve this shortcoming.
Whether you prefer the SKX011 over the SRPD59 or vice versa will ultimately depend on personal preference. Overall, the looks of one watch will likely speak to you more than the other. Furthermore, some collectors prize the heritage and history of the SKX, of which the SRPD59 has none.
Personally, I find the SRPD59 more attractive and a more convenient watch to wear because of the upgraded movement & bracelet, but there are undoubtedly some who much prefer the utilitarian aesthetic of the SKX. Indeed, these are supposed to be “tool watches” and the SKX looks the part much more than the 5KX.
Along the same vein, the shinier looks of the SRPD59 make it easier to wear with a dressier button-down shirt such as an OCBD, something I wouldn’t really consider with the SKX011.
Ultimately, both watches currently linger around the same price point and, if you can, I recommend getting both. If, after wearing them for some time, you find that you much prefer one over the other, then you can still sell the reject online and recoup some of your investment.