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Seiko 5 SRPD77K1 Review: A Worthy Heir to the SKX?

In Dive Watches, Watch Reviews by Zsolt Janka

In this review, we’ll take a look at the SRPD77K1, one of the new Seiko 5 Sports Collection watches. Read on for the full overview.

Seiko’s new SRPD line is a satisfying combination of the remarkable SKX and classic Seiko 5 qualities. Let’s try to find the raison d’etre of this collection through one representative piece: the Seiko SRPD77K1.

Seiko: The Brand

Seiko was founded by Kintaro Hattory. He opened a watch and clock shop in 1881, then established Seikosha factory to manufacture high-quality wall clocks, pocket watches and eventually wristwatches.

It was the origin of the huge company we call the Seiko Group. They made the first quartz movement, one of the first mechanical chronographs and first quartz chronograph. Moreover, they also created many iconic watches like the SKX diver.

A noticable cult following and modding community evolved around this timepiece. The Seiko SKX was launched in 1996 and discontinued in 2019.

Seiko replaced it with the new Seiko 5 Sports collection.

SRPD77K1 cover 2

Watches in this collection have to be automatic. They need to have a durable bracelet and a case with a recessed crown at 4 o’clock. They must be able to show the day and date in a single window, all while being waterproof.

These are the requisites of the Seiko 5 line that was firstly introduced in 1963 (although, based on my observations, the crown style and position is flexible).

The 5KX, as the fans call, may be a new chapter in Seiko’s rich history. If we look at it as a separate watch, not as the SKX’s heir, I am sure it has a glorious journey ahead.

The Seiko 5 Sports

So many colors, so many styles – that was the first thing that came to my mind at first glance.

There is a moderate black dial / black bezel watch next to a ‘Hulk’ imitator (green bezel and dial, just like the famous Rolex). There is an all black model or a case with rose gold coating…the list goes on.

There’s also plenty of diversity in bracelets and straps, and the whole series looks like an intentional palette. I’m sure everybody can find at least one piece that fits their taste, although maybe not their wrist.

Speaking of which, we have to talk about the dimensions of the Seiko 5 Sports watches.

Seiko 5 Sports Dimensions

All of the Seiko 5 Sports models have a diameter of 42.5 mm, 13.4 mm thickness and 46 mm lug to lug steel case.

The lug to lug distance makes it wearable, but bear in mind it’s not a small watch. They seem like any SKX, but they have a display case back and a non-screw down crown.

SRPD77K1 caseback 1340

They resist up to 10 bar pressure, which is more than enough for everyday use. They “lose” the ISO 6425 certification, but with the 4R36 movement it makes sense to wind your watch without having to unscrew the crown.

Further differences from the SKX include the use of normal spring bars instead of fat bars, as well as drilled lug holes for easier strap changes.

The collection basically consists of five categories: Sports, Suits, Specialist, Street and Sense.

Plus a few special editions like the Street fighter, Naruto and Boruto, Brian May edition, the 140th Anniversary edition, the SRPG47K1, the EVISEN Skateboards edition, and the Guccimaze limited edition.

It’s not a secret that Seiko is taking aim at younger generation with these fancy, colorful and extravagant (but still trustworthy) watches.

The Seiko SRPD77K1

I had the opportunity to test this model and write an honest review, and even though it’s just one model, I think it represents the whole collection.

“Creativity is all about the detail” states Seiko’s website under the Sense category to which the SRPD77K1 belongs.

Let’s see if this rings true…

Case and crystal

The case diameter is 42.5 mm and 46 mm from lug to lug. It’s hard coated for a decent surface treatment, which is how it gets the gunmetal grey color.

I wonder how long will it last, but I also think that an aged, faded version of this case will look just as cool.

SRPD77K1 wristcheck 2

There’s nothing special about the unidirectional bezel. It has 120 clicks and does its job without complaint. Its edge matches the case finishing perfectly, of course.

A standard Seiko Hardlex crystal is fitted securely into the case, offering plenty of scratch resistance and general durability for almost any lifestyle.

Dial and Hands

The dial has way more detail than rivals in this price range. The embossed green surface shows its character throughout the day and the orange second hand as it sweeps over its tiny plateaus and valleys.

This SRPD77K1 dial has applied indexes (they’re not painted on like they were on the SKX).

SRPD77K1 macro

The dial pattern also reminds me of the skin of a dinosaur toy I had in kindergarten, which gives me a warm, nostalgic feeling when I look at it.

SRPD77K1 wristcheck

On the dial, we can also see the new Seiko 5 logo. Many people thought this was a fancy Seiko ‘S’ logo, but as it turns out, it’s the number 5.

Also, the SRPD77 can produce quite a light show thanks to the fresh and glow-y Lumbrite paint.


I have never had any problem with the 7S26 movement (in the SKX). Nevertheless, it makes me happy to see a modern movement in the SRPD series.

The 4R36 is a 24 jewels automatic movement. It has hacking and hand-winding functionality with about 40 hours power reserve.

It has an ETACHRON regulator system, a diashock and of course the well-known Seiko magic lever.


It’s a 120 click unidirectional bezel, which means you can only rotate it anti-clockwise, measuring the passage of time in a manual, age-old way.

The color of the coin edge bezel is also gunmetal grey. The insert is aluminum and green, which compliments the dial nicely.


The SRPD77 comes with a 22mm green NATO strap. It matches the aesthetic of the watch; however, my experience is that all NATO straps make the watch look a bit tall and bulky because of the two layers of nylon between the watch and your wrist.

As a side note: I use a method called the slim tuck (not my invention) that lets you reduce the height of the watch, making it sit closer to your skin.

Nevertheless, the strap is high quality and pretty long at 28 cm, and the metal parts (the buckle and keepers) are match the color of the case – a nice detail.

The case has drilled lugs, so changing the strap is pretty easy. This watch would look great on a wide variety of straps.

Pros and Cons

I am absolutely satisfied with the SRPD77K1. If you ask me, the price value ratio is insane, especially considering the fact that this watch is powered by Seiko’s 4R36 movement.

Does it have any drawbacks? Let’s take a closer look at pros and cons on the collection from my point of view.


  • Great quality for the price
  • Ton of color options
  • Reliable movement


  • No ISO certification
  • No need to modify (not necessarily a bad thing)
  • No jubilee bracelet option
  • No sapphire crystal

Of course, these are somewhat subjective, so you may disagree and have your own opinions!

Final Thoughts

The SRPD77 carries on the SKX’s legacy in a new way, so it’s almost impossible to analyze the new Seiko 5 Sports line without discussing the SKX.

You don’t get a proper dive watch, but I’m sure you’ll be fine if you don’t pull the crown out underwater. Yes, a screw down crown would be nice, but this crown makes sense because you can wind the watch or set the time without messing up the threading.

So, who’s the SRPD line for? Seiko is marketing it toward a younger crowd and anyone who likes casual, colorful watches. But really, anyone who likes Seiko will want to check these watches out.

That said, the SRPD77K1 isn’t right for everybody. It’s not a conventional piece. It’s exciting and has lots of character.

But looking at the collection as a whole, the SRPD77K1 isn’t the most traditional or most flamboyant watch. In my opinion, it’s the perfect middle-of-the-road Seiko 5 Sports watch.

About the Author

Zsolt Janka

I'm a university student with a passion for horology. I collect watches and document the memories with them. As a side effect, I try to improve my photography skills, and recently write, too.