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Seiko Sumo Review ‘Blumo’ SBDC033

Seiko Sumo Review – ‘Blumo’ SBDC033

Halfway through 2016, I was fortunate enough to travel to Tokyo, Japan for business for five weeks.  Ahead of my trip, I was making a mental note of the bucket list items I wanted to cross of my list that involved Japan;  Visit Kyoto.  Cross that famous, crazy crossing at Shibuya.  Watch the oddly compelling retro Rock ‘n Roll dancers in Yoyogi Park.  Eat sushi for the first time ever (yes, I know!). Visit every watch store in Tokyo.

To achieve the lattermost, I hunted the internet before flying out, finding out where I should head for the best watch places for new and/or second-hand watches.  After all, for those of us with a penchant for Seiko, Citizen, Casio and the like, Japan is a veritable Mecca!

Although I spent most of my weekends walking 20-30km per day from one place to another, I already knew in my heart what my Japanese souvenir would be.  A blue Seiko SBDC033 Sumo or, as it’s more affectionately labelled by those in the know – “Blumo”.


I found my Japanese beauty in the Ginza Bic Camera store, a hyperactive assault on the senses which needs to be seen to be believed, where almost an entire floor is set aside for watches, from Swiss legends to Japanese, well, legends.

There are a lot of wonderful watches that form the Japanese domestic Seiko watch range which many collectors aspire to own pieces from, and most of them were on display here. The entire Marine Master line-up. The highly desirable Seiko Alpinist. The exquisite, elegant Seiko Sumo. My heart was already set on one in particular though, and it was love at first sight when I glimpsed it.

I have always thought of the Sumo as a “poor man’s Marine Master” as, despite having many design differences from the Marine Master range, there are certain elements which edge towards it, whilst still being affordable. 


Certainly, many will find that the Sumo is the point where Seiko’s dive watches start to transition from beaters into a dressier style, without losing their functionality and durability. This iteration of the Sumo, the SBDC033, is a slight update to the hugely popular SBDC003, with the differences being a slight change to the dial design (with the addition of the Prospex logo) and upgraded lume, but otherwise pretty much the same watch.

Coming on a 20mm, solid stainless steel bracelet, the Sumo has divided the opinions of many with the case diameter measuring 45mm without the crown, and some say that the bracelet is too thin to accommodate a larger-size watch.  Personally I don’t agree, despite being a fan of larger bracelet sizes myself, this one somehow works and I’ve never given it a second thought, aside from when considering after-market straps.  The quality of the bracelet is excellent, in my view, but I have also been far less picky about the Seiko standard bracelets (SKX Jubilee aside) as I think they represent excellent quality for the money and even so, this Sumo one is a perfect match for the watch you’re getting.

For a larger watch, it wears quite small, even though I have a number of 45mm watches which sit nicely on my 7 1/2 inch wrist, this one doesn’t feel oversized in any way, which might normally put some prospective Prospex prospectors off.  At 14mm high, it’s not overly chunky either, meaning that it should slip deftly under most shirt sleeves without too much effort, allowing it to also sneak out from time to time and impress those who happen to be looking in the right direction.


The dial and bezel come in a glorious blue, which catches the light superbly, one of the main reasons I went for this over the black SBDC031.  The dial has wonderful, raised indices which glow in the dark like a concentrically perfect circle of sleeping fireflies in glue once the lights go off, as do the hands which are placed somewhere between the thinner, more elegant Marine Master hands and the designed-by-a-five-year-old hands of the SKX series.

Inside the watch you should hopefully find the very robust and user-friendly 23 jewel 6R15 automatic movement, which allows hacking and manual winding and comes with an impressive 50 hour power reserve, all of which should keep on merrily ticking underwater with its 200m rating. The crown is etched with the Seiko “S” and can be found at the 4 o’clock position, much like the SKX range, but it works here and screws and unscrews far more smoothly than its poorer cousin.

The case itself has beautiful curves to it, with the rounded case merging into the more angular bezel from the side in a manner that causes the edges to become an elegant shroud of sorts, which adds additional charm to the overall shape of the watch.  The lugs are drilled, allowing for some rapid and straightforward strap changes, should that be your thing… and it should be your thing because the Sumo comes alive on NATO or leather straps and offers up new ways to love your Sumo.


The crystal is Hardlex as opposed to Sapphire, but there is already a booming aftermarket for Sapphire alternatives, should you opt to go down that route.  It is flat to the bezel, rather than rounded, although this is pretty standard for the current diver’s watch range, and is in keeping with its modern aesthetics.

A small, huge caveat, however.  The SBDC033 is a gateway drug of sorts, as once you’ve fallen in love with this one, as I’m confident you will, it opens up a whole new risk-zone due to Seiko from time to time offering limited edition Sumo, with orange dials, white dials, different hand sets, ceramic bezel inserts, not to mention the aforementioned Marine Master watches which seem all the more attainable now that you’ve entered the Sumo ring.

Mine is undoubtedly my favourite Seiko presently (from a selection of 9) and will be going nowhere fast as it sits so beautifully on my wrist and has allowed me entry to a club of Sumo devotees who are pretty vocal about their adoration of the watch. 

So do yourself a favour.  Pop over to Tokyo.  Walk endless kilometres and visit every watch emporium you can find, but strongly consider getting yourself a Sumo amidst all the delights on display and see what all the fuss is about. Or buy one online… whatever.

Wrapping up

I hope you enjoyed this Seiko Sumo Review!

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  1. Post comment

    Hi Tom,
    Firstly, great article. I actually read it twice (is that normal). I’m new to the watch world and started with buying a Seiko Presage SARW011. I’m now looking to buy a Prospex. I love the SBDC005 and am wondering if they will release a SBDC055, similarly to the SBDC033 story. What do you think? Also, do you think the SBDC005 has too much pop, making the SBDC033 the better choice? Lastly, I love that leather strap in your photos, what strap is it?


  2. Post comment

    very nice – looking to add another diver to my collection and the Blumo is up there – I already have a SKX011J (orange) and the black and gold pointy toothed monster and recently sold my SKX009. I just flipped my Gruppo Gamma Dive Master and my Chris Ward Trident Pro and have a gap that needs another Seiko really.
    common sense says it should be a Cocktail Time but I’m a scruff bag and really prefer dive/sports watches to dress ones which I inevitably end up trashing.
    great article


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