The Seiko community, and yes, not just the modders, let out a collective sigh of disappointment when the SKX line of divers was discontinued. It has been a popular choice during its run, and became a household name for price-conscious divers watch fans.


SKX Fans in 2019


Seiko fans quickly moved on with the release of the SRPD 5 Sports line however, which proves to have most of what it takes to fill the shoes left behind by the SKX. Many even lovingly call it the “5KX” line as a sign of approval that it is indeed, the successor to the retired diver line.

And with the more recent release of the SRPE 5 Sports watches, it is clear that Seiko is moving away from the budget divers watches and into the budget sports watches category. Is this simply a ploy to get more people to get a Prospex watch for their diving collections, or are Rolex Explorer style watches really the way to go?

Let’s discuss.


Looking Back at the SKX

When talking about the things that made the SKX line good, where do you even begin?


The little diver that could. Source: Hodinkee


How about the 200m depth rating of the SKX007 that was killer in its $300 price range? That’s enough to pass an ISO 6425 certification, which by the way includes these rigorous tests:

  • Condensation test
  • Saline water resistance test
  • Pressure test
  • Shock resistance test
  • Magnetic resistance test

The size hits a sweet spot of 42.5mm too, which is a great size for most wrists and doesn’t look overly large - a common theme with diving watches. A small detail to mention is the crown position at 4, making it more comfy to wear as the crown and crown guard will not directly hit your wrists.


It's a healthily growing niche


Another good thing about it is not about the watch itself, but the community it fostered. For many, the SKX007 was the affordably priced gateway watch into the world of watch modding and collecting, bringing hundreds of thousands, if not millions of people together through a hobby. And that, modfam, is just beautiful.

That said, there are things about the SKX007 that should stay in the past, like the 7S26 movement that lacks hacking and hand-winding support. Not to mention the accuracy. It was a reliable unit, but has much room for improvement.


SKX vs. the 5 Sports Line

We already pitted the SKX and the SRPD face to face before and here are the highlights:



From the SKX007’s 7S26 to the SRPD and SRPE’s 4R36, the jump gave Seiko fans the hacking and hand-winding features that they’ve been asking for for a long time. Hacking is the ability to stop the seconds hand to set the time more accurately, and the hand-winding simply means you can power up the movement by rotating the crown with your hand. Small things but big improvements. 


If they simply refreshed the SKX with the 4R36, people would have been ecstatic. Source: WatchReviewBlog


If you want to add hacking and hand-winding features to your SKX007, you can easily do so by replacing its stock 7S26 with an NH36, an unbranded but Seiko-made movement, available here.


Water Resistance

On this front, the new Sports line actually goes backward and only rates the SRPD watches at 100m, which is only half of what the SKX can dive to.


Source: Beyond the Dial


While not everyone actually takes their watch diving in deep waters, knowing that your watch is capable of 200m was a bragging right. Much like how computer GPU brands brag about how much VRAM their newest model has, or how many megapixels Samsung phone cameras can shoot, the water resistance rating was a big talking point for dive watches.

The Seiko 5 Sports line is also sadly not ISO certified. 


Crown and Caseback

One reason for the lower dive rating of the newer Seiko line is the push and pull crown, as opposed to the screwdown crown of the outgoing SKX line. Having a screwdown crown and coupled with gaskets makes it better for water and shock resistance.


If you had to choose between a better water resistance rating and hacking and hand-winding capabilities, which would you choose? Source: Reddit


As for the caseback, the SKX has a stainless steel, decorated plate while the 5KX watches feature a fancier see-through caseback.


Variety of Design

The SKX007 is a stainless steel watch with a black bezel insert and a black dial. The SKX009, the only other variant, is a stainless steel watch with a blue and red insert and a dark blue dial.


Seiko didn't play around much with the SKX007. Source: Watch Gecko


Not exactly full of choices.

For the SRPD and SRPE watches though, they have so many variants that they had to separate them into 5 other categories: Sports, Suits, Specialist, Street and Sense. Not to mention the many collaborations that Seiko is using this line with, which brought us the Seiko Street Fighter watches, the Seiko Naruto watches, and more.

How Moddable are They

The SKX007 just has way more mod parts that are available for it compared to the newer Seiko 5 Sports series. We think this might be due to the fact that there were only 2 SKX007 variants when it was released, making it the perfect canvas for Seiko modders to exercise their creativity and customise one to their liking.



 They look modded already! Source: Watches by SJX


With so many OEM design choices for the SRPD, there’s less of a need to change a base watch, but still, you’d be glad to know that there are a lot of cross-compatible mod parts between these two lines of divers. A lot of mod parts for the SKX007 can be used for the SRPD Sports series, and you can find the complete compatibility list here.

The SRPE Joins the Fray

You can describe the SRPE as being simple, but well-executed as a watch. It still has a presence on the wrist, though not as overt as its diving predecessor. The non-rotating bezel is minimalist, making it almost like a field watch in appearance, especially the ones that come standard in a NATO strap.


Designed with purpose and vision. Source: Bellatory


The hands and dials are extremely legible, and the simple chapter ring complements it quite nicely. The sideways 5/S logo is featured prominently under the main Seiko brand. The case is a mix of polished and brushed to help lessen the glistening effect which can be distracting for a sports watch. It still features Seiko’s good ol’ hardlex crystal, which is now mounted right on the bezel instead of within it.

It’s a look you can’t go wrong with.

Powering the ensemble is the upgraded 4R36 which is pretty much a 7S26 with hacking and hand-winding and better accuracy. It may not be the most beautiful or the most intricate calibre in the world, but Seiko chose to show it off with a glass display caseback nonetheless. A surprise decision, but a quite welcome one.


See-through always makes things cooler. Source: Dappered


The SRPE vs SKX/SRPD Lineup

There’s not much to compare between the SRPE and SRPD watches because they are all under the Seiko 5 Sports mantle. Aside from the watch being mounted on the bezel, these two are pretty much the same.

When comparing the SRPE to the SKX however, the difference is glaringly obvious - most of the Seiko SKX mod parts are not cross-compatible.


Why Seiko, why?


First, we want to make it clear that when we refer to the SRPE, we talk strictly about the Seiko 5 Sports series of watches. We state this as the SRPE model prefix is also used for Seiko Samurais. As an outlier; the SRPE83K1, which is also part of the Seiko 5 Sports Sense collection, is actually compatible with SKX007 parts.

That said, everything else in the Seiko 5 Sports collection is incompatible. You can still swap out the hands, dial and movement with mod parts made for the SKX007 but aside from that, nothing else. That is why we are releasing SRPE mod parts that are in their own separate category from the SKX/SRPD parts.


Which SRPE Parts can be Modded?

In terms of moddability, the SRPE Seiko 5 Sports watch is still very much in the discovery phase. People are just starting to experiment with it as a modding base, and not a lot of suppliers offer parts for the as of yet.

namokiMODS does have a few parts available for SRPE modding already, starting with the case. If you don’t wish to buy a brand new watch just to take it apart and build a new one, you can always start with a bare modding case, like our Polished SRPE Pilot Case. It already comes with a matching bezel and crown to make it easier to work with!



Fan of vintage? We have an aged steel version as well.

As for bezels, we also have you covered with our coiled and fluted versions that are available in PVD black, gold, or polished stainless steel. Do note that these are not compatible with our NMK917 and NMK918 cases, but they should fit perfectly on OEM cases.



You’d want to upgrade your crystal from Hardlex to the much better Sapphire glass, and you can with our flat or double-domed variants. These are more scratch-resistant and are coated with anti-reflective coating that makes the SRPE even more legible in bright environments.

Want something more premium looking than NATO straps? Check out our bracelets that will help turn your field/sports watch into a classy Explorer looking watch.


Bottomline: the Best of the Bunch

The SKX007 is still king when it comes to mod parts availability, and with plenty of information and tutorials out there, this is also the best model for newbies when trying their hand at modding for the first time. It is also the no-brainer choice for fans of the diver watch look.

The SRPD and SRPE lines are more appealing to the new generation of watch collectors, with their more sleek and minimalist constructions and variety of OEM designs, not to mention the collaborations with other pop culture brands. They have a clear vision and demographic in mind for the Seiko 5 Sports, and we believe it can succeed despite the persisting demand for the SKX.

What are your thoughts? We’d love to hear them in the comments!

December 16, 2021 — Jeremiah A

Leave a comment

Please note: comments must be approved before they are published.