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The Seiko Sumo is a watch you tend to see recommended over and over again in various media; there’s little wonder why. Cool design, in-house Seiko movement, and a case construction with a reputation that precedes it.

There’s a couple of versions of the “Sumo” – the 003 was the original, with “Scuba” printed above automatic on the dial. This model, the 033, replaced the original and the main difference is the Prospex “X” logo in place of “Scuba”. Prospex stands for “professional specifications” – and is the collection of more premium Seiko divers.

Enough waffle, I’ve had this watch for almost a year now and I thought it was about time I knuckled down and got on with the review. Let’s take a closer look.

The specs

The case

The Seiko Sumo case is epitomised by beautiful craftsmanship and flowing lines. I had pretty high expectations; it’s certainly delivered. It has really crisp edging, especially at the base of lugs where a handful of angles meet.

The polished and brushed finishing is flawless; I especially like the central brushed channel with a polished top and bottom.

The screw-in crown has great grip and a beautiful shapely S deeply engraved on the end.

Drilled-through lugs are always helpful; it allows you to remove the bracelet easily from the outside.

The bezel flowers out aiding the grip, and it nestles within flanges of the case on both sides, so it’s only usable at the top and bottom. I actually really like this as I only ever use the bezel at the top and bottom and it accentuates the flowing case. the insert is spotless, and the action is buttery smooth.

Now we come to the most important element you should think about: the hardlex crystal. Whilst it is harder and more scratch resistant than mineral crystal, it’s still gutting that on a ~£350 watch it isn’t sapphire. What’s more, as it’s domed, it’s pretty liable to scratches (which has happened to me on this very watch). Saying that, it does provide a beautiful collection of reflections which exemplifies the dial well.

The screw-in caseback is brushed with a central polished section with the usual wave you often see on Seikos. Various watch details are deeply engraved around this.

The dial

There’s nothing too outrageous when it comes to the dial – Seiko’s primary concern is that of making it as legible as possible for diving: the hour markers and hands are bold, and legibility is excellent.

The applied hour markers are lumed with a polished border around them – trapezoids at 6 and 9; a triangle at 12, with the remaining markers as discs.

The hands are an interesting unique design; I like the subtle lumed block on the seconds hand, with the minutes and hour hands taking a rather angular approach which mimics the ethos of the case. These also have a polished base to them, so all the elements catch the light really well making a beautiful impression to the eye.

Can anything be better than Seiko’s Lumibrite lume? I’ve yet to find a lume that charges faster, glows brighter, and lasts longer. Simply put, it’s the point of reference for all other lumes to try and beat.

The date window is simple; it is cut out of the dial with a white border. It’s neatly done as you’d expect, and the wheel is white with black text – very legible.

I like the deep rehaut, which contains a minute track within as it provides a bridge between the dial and the bezel. The printwork is all crisp and delicate, including the microscopic text at the foot of the dial.

The bracelet

Is a 20mm wise bracelet too thin for a 44.5mm diameter watch? Many tend to think so. Personally, though, it doesn’t really bother me. In fact, it’s pretty comfortable.

The links are fitted together using Seiko’s weird pin and collar links, which tends to be a bit awkward when resizing. Check out my video on how to resize these little blighters.

The links are primarily brushed, with polished sides and a polished channel either side of the central link. Nice alternating finishes keep the eye interested, however, the quality isn’t quite up to the same standard as the case.

The double locking buckle is solid and very dependable. There’s a huge top locking flap with the Seiko logo deeply engraved within, and a locking button either side to open it up. It’s fully brushed bar the polished shoulders, and it also boasts 4 micro-adjustment points plus a diving extension.

The movement

The movement powering the Seiko Sumo is the Seiko 6R15. Specs include 50 hours power reserve, hand and automatic winding, hacking seconds, and 23 jewels.

The chances are that this movement will perform for many, many years. I know Seiko watches with mechanical movements that have ticked along happily for literally decades without a single service. There’s no doubt you’ll be getting a rugged, hard-wearing movement.

Final comments

By reading this review, you’re obviously interested in what the Seiko Sumo offers. Really, the key questions you need to ask yourself are primarily whether you are ok with the hardlex crystal, and on a slightly more minor level if you don’t mind the width of the bracelet (which doesn’t actually bother me in the slightest). I’m a fussy guy when it comes to spending money on watches – and whilst I’m annoyed that the crystal on this watch has scratched it actually (and surprisingly) hasn’t marred my overall impression of the Sumo. And that’s saying something.

I completely understand that some of you may completely disregard this watch due to the crystal, but if there’s the slightest intrigue then I’d suggest you succumb to it – as you’ll not regret it. The overall fit and finish, as well as the design, is sublime.


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View comments 10


  1. John Burtis

    I trusted you on the Invicta and purchased one and I am very happy. Perhaps it’s time or another Seiko. Thank you for your marvelous reviews!

    1. Joshua Clare-Flagg

      Thank you John!

  2. Jimbo Jonez

    Totally agree – superb rugged tool watch that is on the next level to the SKX et al. I recommend getting a Crafter Blue strap, they are specially made for the Sumo and transform it. Keep up the great reviews.

    1. Joshua Clare-Flagg

      Thanks for your kind words!

  3. Jerry

    Woah the Seiko Sumo is definitely a very pretty watch. Your close up pictures are very high quality and showcased its fine points – the case construction look very very sharp and good!

    I’m not trying to nitpick here but I think the bracelet connection to the lugs is a bit lowered compared to the lug surface. A bit odd there I would say.

    In terms of the movement, what kind of accuracy are you getting? I’ve read this review here ( where the guy said his Sumo accuracy become bad (about 20-30 seconds per day) in just 3 years. What do you think about this? Is it a typical Seiko issue or that guy was just unlucky to get a lemon?

    1. Joshua Clare-Flagg

      Thanks very much for your kind words! The accuracy I was getting was +10.5 seconds a day, so acceptable I’d say. Mechanical movements do tend to misbehave in time, usually due to magnetism and the fact they need maintaining such as new oil and cleaning up, but that to me just sounds like it’s due a service.

  4. Filip

    Wow such a great review. Would you recommend blumo or seagull ocean star? I can’t decide 🙂

  5. Tim

    Great review! And the photos really shows the quality workmanship of the watch. Do you have a trusted seller online for the Sumo?
    Thanks for sharing!

  6. Tim Larson

    Very nice review Joshua. Especially your photos that really shows the excellent workmanship of the Seiko Sumo. Keep up the great work! /Tim

  7. Cj

    Just bought mine 2 days a ago that’s why I’m here. I would like to ask if this watch would go high on value someday or not? Coz if not, I’ll just rock this $500 watch.

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