Seiko Prospex ”Sumo” SPB103j1 Review & Complete Guide
Seiko – the brand that has become synonymous with affordable and qualitative affordable timepieces. In fact, we would even dare to say that Seiko’s watches are some of the best value money can buy if you factor in finish, quality, and durability.
It is today one of the largest watch manufacturers today if we look at production numbers, and its great popularity has led to the brand releasing countless models in terms of design, purpose, and also price. Seiko’s watches range in price from less than 100 USD up to the thousands. Paying more than a thousand dollars, or even more than five hundred dollars for a Seiko is not something everyone is willing to do, but if we look at some of these watches in detail, it becomes very evident that you really get a lot in return. And in many cases, they still prove to be great value for money.
So that is exactly what we are going to do in this article.
In this post, we are reviewing and looking closer at the Seiko Prospex ”Sumo” SPB103j1.
Seiko Prospex ”Sumo” SPB103j1 Review
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Amongst watch enthusiasts, Seiko’s sports and dive watches have proven to be the most popular. Seiko has a long history of making professional dive watches, and these vintage watches today have a large devoted following of collectors.
Backed by its proven history, Seiko continues to produce professional dive watches under the same ethos. One of which is the Prospex ”Sumo” SPB103j1
The Prospex in the name stands for ”Professional specifications” and simply means that the watch is built according to the needs and wants of professionals. These watches are made to handle seriously harsh conditions, including those that professionals subject them too.
In addition to this, the SPB103j1 is also a ”Sumo” watch. What does this mean? Essentially, it refers to the case design of the watch. The Sumo was originally presented in 2007 and the name actually doesn’t come from Seiko themselves but has been born by enthusiasts – like so many of the other Seiko nicknames such as the Tuna. Whilst the origin of the name is not exactly confirmed, you could assume that the name refers to the watch being bulky and sturdy like a sumo wrestler.
Because already at first glance, you will notice that the Seiko SPB103j1 and all of the other Seiko watches are big, bulky, and have a hefty weight. This is part of the personality of the Sumo, which of course goes very well with the purpose of the watches.
What is particularly interesting about this design is that its design has remained more or less unchanged since it was first presented, which goes to show it is a truly timeless design. Something watch enthusiast love, and proof that Seiko has done a great job with the design.
With that said, the Seiko Prospex ”Sumo” SPB103j1 is a serious dive watch made to perform underwater and to be able to handle shocks, bangs, and whatever harsh conditions professional divers may subject it to.
The SPB103j1 was released in 2019 and is the successor of the previous model SBDC031 which it replaced.
If you are looking for a professional dive watch that can do all of that, and have a seriously sporty presence on the wrist, the SPB103j1 ”Sumo” may just be the watch for you.
Let’s dig in!
Seiko Prospex ”Sumo” SPB103j1 case
The watch is presented with the now-iconic ”Sumo” case which is, as mentioned, large, bulky, and sturdy.
The stainless steel case has a diameter of 45mm, a thickness of 13.5mm, and a lug-to-lug measurement of 52.5mm. See, I told you it is a bulky watch. With that said, it does have quite a bit of presence on the wrist and is, therefore, most suitable for men with medium to large wrists and those who enjoy the wrist presence that large watches have.
At this price point, we expect a well-finished case, and that is exactly what Seiko delivers. The lugs have a really nice ”curved” design, and is satin-brushed on the top, which, depending on how you see it, could be considered bevels. The inside of the lugs, however, also have bevels, but this time, it is polished. As a nice contrast, the sides of the case are polished.
Crown guards would simply make this watch too large and bulky, so Seiko has decided to skip the crown guards for the Sumo, which is a wise decision. Still, the crown is recessed into the case and therefore sits somewhat protected. Naturally, for a dive watch of this caliber, it has a screw-down crown. The crown is quite large, but so is the case, so they go very well together. Speaking of the crown, Seiko has positioned it at the 4 o’clock position which is iconic for many Seiko watches. This keeps it from digging into the wrist, which is a good thing, particularly for a watch of this size.
This is a serious dive watch, so naturally, it has a good water-resistance. The Sumo SPB103j1 has a water-resistance of 200m/660 feet which makes it suitable for swimming, diving, and essentially any type of water activity.
A dive watch also needs a unidirectional rotating bezel for measuring elapsed time, which this has. The bezel is quite wide and has a bold green aluminum insert. The Arabic numerals on it are printed in silver and are large for optimum legibility. At 12 o’clock, it has a luminous dot so you can read it even in low-lit conditions.
At its very edge, closest to the crystal, it is sloped. This means the bezel sits taller than the actual crystal, which keeps it protected and minimizes the risk of getting scratches on it. Speaking of the crystal, this watch is equipped with a sapphire crystal. This is something that the predecessor did not have. A big improvement indeed.
If you turn the watch around, you’ll find a solid steel screw-down case back with the iconic Seiko tsunami emblem.
Photo: Fratello Watches
Seiko Prospex ”Sumo” SPB103j1 dial
The dial is definitely the highlight of this watch as it has a lovely vibrant green color with a beautiful sunburst brushed finish. Due to the sunburst effect of the dial, it reflects the sunlight beautifully, and changes look from a fir green to a striking bright emerald color.
With the green bezel and dial, some may even say it is reminiscent of the Rolex Submariner ”Hulk”…
As a dive watch should, the SPB103j1 offers great legibility. It has large hour markers and hands which provide excellent contrast against the green dial.
The watch has applied hour markers with polished metal frames and applied Lumibrite. The minutes and hour hands are sword-shaped and are quite wide.
At 3 o’clock, we have a large date window with a white painted frame around it. This of course helps make it more practical, since after all, most people will wear this watch as an everyday timepiece and not below the surface, where you don’t really need to know what date it is.
For additional depth, the dial also has an angled chapter ring around it.
Overall, the dial is very well executed and manages to stay true to the Sumo design, whilst adding a very vibrant colorful touch. The lime on this watch is great and glows brightly for many hours, which we expect in a dive watch.
Photo: Fratello Watches
Movement
Powering the Seiko Prospex ”Sumo” SPB103j1 is the in-house Seiko caliber 6R35.
Since 2007, the Sumo watches used the 6R15, and whilst this proved to be a trusted, sturdy, and reliable workhorse movement, Seiko decided it was time for an upgrade for this watch and therefore, it is powered by the latest version, the 6R35. This movement is still the same base but has been improved and refined.
This movement beats with a frequency of 21600 BPH/3Hz and has 24 jewels. The movement has a power reserve of 70 hours and displays minutes, seconds, hours, and the date. The date is adjusted through a quick-set function.
The improvements from the predecessor include an improvement from 50 to 70 hours. Like the predecessor, it has hacking seconds and manual winding functions. It has, however, jumped its jewels to 24.
Photo: Fratello Watches
Bracelet
The watch is presented on a three-link satin-brushed bracelet with polished edges on the middle links. The bracelet has a diver’s extension and safety clasp.
The bracelet goes very well with the sporty design of the watch, but some may be surprised to see a 20mm bracelet for a case of this size. In our opinion, it works very well.
The good news is that if you want to change to a different strap or bracelet, you can easily do so thanks to the drilled lugs which makes changing the bracelet a breeze.
The bracelet is very beautifully finished and feels solid. Generally, affordable watches tend to compromise on the bracelet the most and have things like folded links and hollow end links which results in the impression of poor finish, but with this bracelet, Seiko shows that you actually get your money’s worth.
Photo: Fratello Watches
Specifications
- Movement: Seiko in-house caliber 6R35
- Frequency: 21600 BPH/ 3 HZ
- Power reserve: 70 hours
- Diameter: 45mm
- Thickness: 13.5mm
- Lug-to-lug: 52.5mm
- Lug width: 20mm
Conclusion
This watch is available in two versions. First, we this watch, the green version with reference SPB103j1. Then we also have the SPB101J1 which is presented with a black dial, which may be suitable for those looking for a watch that is less bold and has more of a classic dive watch design.
With the green bezel and bright green sunburst dial, the SPB103j1 definitely stands out from the crowd and is a fun and refreshing dive watch that is a contrast to the mostly monochrome black dive watches on the market.
The SPB103j1 is a large and bulky watch with a sporty appeal. It’s definitely not a watch for everyone, but if you have large wrists or just enjoy big sporty dive watches, you’ll likely enjoy this one. It is based on the now-iconic and appreciated Sumo platform, is well-finished, durable, and reliable. As a serious dive watch that holds better quality than Seiko’s most affordable alternatives, it still offers great value for money.
The Seiko Prospex ”Sumo” SPB103j1 is available to order on Amazon.
Main Photo: Monochrome Watches
