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What's With the Seiko SUMO?


In 2007 Seiko introduced a watch without any fanfare. Just a simple 200 meter diver watch that had an odd nickname and a certain quirky feel to it that begged the question "do you love it, or do you hate it." In my opinion, it was a gamble for Seiko, as competition was getting very fierce and one of it's Swiss counterpart, OMEGA, was coming out with a new diver watch, the Planet Ocean, which OMEGA felt would kick competition. SEIKO definitely needed a "shot in the arm", they really needed a breakthrough. They knew they couldn't compete with its current line up. SEIKO had to produce a watch that had a slightly higher price point than the other divers it had in the market and introduce one that could give it the respect it felt it deserved from its swiss counterparts, while still being competitive in the one area where SEIKO felt they can beat out the competition - the price. The product was a watch that was not only an iconic one, but was also 1/5 the price of the Planet Ocean, which gave it the title the "Omega Planet Ocean killer"; and it was introduced to the market without any fanfare -- they just let the watch do all the talking.

The SEIKO SUMO appealed to that set of watch collectors that needed to see something "uniquely new" which not only had a luxurious touch but also an "expensive" feel as well. It had to be a heavy watch that was not only solid, but creatively shaped which gave people something to talk about it. And finally, it had to be "uniquely SEIKO", that would allow the brand to take the modern SEIKO diver's watch to a whole new level.


The SUMO was introduced with three color variants, the "First Three": the Black SUMO referenced as SBDC001 had a certain traditional diver vibe to it in the mold of the Rolex Submariner, and yet was very different as it was the very first one that was introduced with a new set of stylish minute markers on the bezel using a never-before seen but uniquely-styled font that is purely Seiko. The Blue SUMO referenced as SBDC003 was the crowd favorite and it was, at that time, my choice for my very first modern Seiko after dabbling with vintage divers whose prices were continuously going through the roof. This variant had become the ultimate crowd favorite as it took a life of its own when collectors gave it its own code name, the "BLUMO." A fitting nickname to a watch that was on the wrist of most of the SEIKO collectors I knew more than 10 years ago. Finally, the third variant was the least liked amongst the three, the orange dial variant, referenced as SBDC005. It had all the same elements: 45mm case size, 20mm lug size, same font on the hour markets, crown at the 4 o'clock and signed "S", but it was the only one that came with the rubber strap. Somehow, I can't help but feel that SEIKO created the orange variant not to appeal to collectors, but just so that they have a third variant to complete its cast of its SUMO line up and give the Seiko audience a third choice. Unfortunately, and if I recall correctly, the Orange variant was not very popular, so Seiko stopped production. It kept producing the black and blue variants, until they released the SBDC031 and SBDC033 with the Prospex logo. It’s important to note that Seiko never came up with an Orange variant with the Prospex logo, which should have been the SBDC035, an indication that the 005 was not very popular. It's funny though, as I look back, I regret ignoring the 005 even though I was told so many times to get all three color variants by a friend of mine as he proudly displayed all three colors in the leather watch case he had just purchased. And, for collectors like him who had the foresight to get the SBDC005, that contrarian view paid off handsomely. Because of the less supply out in the market, prices in the secondary market now reflects this as the orange variant is priced 2 to 2.5x the price of the black and blue variants, if you can find one.


But what's with the name? I believe there were basically two reasons where the SUMO got its monicker, one was visual while the other was more tactile. Visually, the nickname SUMO is believed to come from the visual representation of the 12th hour market of the watch that is derived from the "Mawashi" or the underwear worn by Japanese Sumo wrestlers during a a wrestling match. The unique shape of the hour marker resembles the shape of the underwear as the big belt goes around the wrestler's waist that is represented by the flat long top of the hour

marker as it drags down its two legs on each of the side. Both sides represent the two legs and the black portion of the marker represents that portion of the underwear that envelopes the crotch. It is important to note that the SUMO is the only Seiko watch whose 12th hour market is a visual representation of the name it was given. One can't see other Seiko watches that have their names that are visually represented in its design. I mean can someone explain to me why the Samurai is named after those elite Japanese warriors who practiced martial arts in pre-industrial Japan, and why the SPORK is named after an eating utensil which is a hybrid of a spoon and a fork. One has to go up the level of the Grand Seiko line-up where the nicknames given are visually representative of the design of the watch....such as the famous Snowflake or Iwate dials of the SBGA and SBGJ series of GS. (but I will reserve that topic for another blog)


From the tactile perspective, one has to wear the SUMO in order to understand why the nickname sticks. With it's 45mm diameter case supported only by a 20mm lug size makes it look "top heavy" and dangly, but that feeling is just an imagination. The strong support base of the watch as it falls down one's wrist feels just that -- STRONG. Not a clunky watch, but a well thought of feel from a physics perspective. The curved lugs as it is surrounds the endlinks of the bracelet gives it the strength to support the big case. Imagine a sumo wrestlers with a huge body and small legs, but has enough strength to not only support the body, but also gives the wrestler the added thrust from the strength of each stretched leg. A description one can only feel and understand if they own a Sumo and wear it everyday.


Overall, the watch is a perfect daily beater that feels neither clunky nor heavy. The way it envelopes the wrist allows it to stand out and it's overall design shouts out that it is a serious watch to be worn by serious watch collectors. The biggest bonus is the price point which definitely made it a great buy over its other Swiss diver counterparts (the "First Three" retailed for $500 or a little over Php20,000 when it was released). So, did Seiko's gamble payoff when it released the first Sumo almost 14 years ago? I think it did and if the number of new Sumo models that were introduced over the last 14 years after release of the first three is an indication, I think Seiko DEFINITELY hit the jackpot! They definitely leveraged on the success of the "first three" and came out with all kinds of new SUMOs, even daring to raise the prices of these watches by attaching the two words to justify the price: "LIMITED EDITION" or even adding a fancy box and attachments to price the watches 3 to 4x the original price of the first three SUMOs and maybe even becoming more daring by combining a variety of colors on the dial and bezel and yet maintaining the visual representations and feel of a natural Seiko SUMO. In other words, Seiko definitely milked the brand and is continuing to do so. If I am not mistaken the release of the SPB175, 177 and 179 are the latest SUMOs that were released and the brand has not let up and I believe will continue to be relentless to take advantage of the SUMO following created by the "First Three."


I was lucky enough to get an answer to my crowdsourcing post on the Seiko Watch Club of the Philippines (SWCP) Facebook page, and thanks to one of the best and more serious collectors and dealers of Seiko watches in the bouyant secondary market I was able to list down most, if not all the reference codes for all the SUMO variants that were introduced since the introduction of the first SUMO. We both counted a total of 25 new reference codes, from the introduction of the "first three":


First Generation (1st) Non-X Dial -- "First Three"

  • SBDC 001 (black dial)

  • SBDC 003 (blue dial)

  • SBDC 005 (orange dial)

Limited Edition First Generation (1st)

  • SBDC 017 (yellow Sumo)

  • SBDC 019 (Green Japanese Limited Edition)

  • SPB029 (White dial)

  • SPB031 (Green with yellow markers) 50th Anniversary Prospex Issue

Second (2nd) Generation - with Prospex X dial

  • SBDC 031(new version of SBDC 001)

  • SBDC 033 (new version of SBDC 003)

  • SBDC 057 (Pepsi with Prospex)

  • SBDC 069 (Blue with yellow second hand)

  • SZSC 004 (Green with yellow second hand Limited Edition)

Limited Edition Second (2nd) Generation

  • SBDC 027 (Black dial) 50th Anniversary Prospex Issue

  • SPB 055j Purple Bezel with Blue Dial) International Edition Seiko Prospex Zimbe Sumo

  • SBDC 049 (PADI Sumo)

Third (3rd) Generation -- with a 6R35 movement combined with a small font bezel

  • SBDC 081/SPB 103j1 (Green with prospex)

  • SBDC 083/SPB 101 (Black with prospex)

  • SPB 125 (Black Series Limited Edition)

  • SBDC 097 (Anthracite Sumo)

  • SBDC 114 (GINZA Limited Edition)

  • SBDC 099 (Deep Blue Sumo Sapphire)

  • SPB 175 (Ice Diver Gray Dial)

  • SPB 177 (Ice Diver Green Dial)

  • SPB 179 (Ice Diver Blue Dial)

Limited Edition Third (3rd) Generation

  • SBDC 113 (Blue dial with Green second hand prospex) Japan Edition

  • SPB 192 (Root beer colored variant)

  • SPB 195j1(Green with red second hand Limited Edition)

  • SPB 194j1(Sumo Okinawa Variant, Zimbe Sumo)

(I am not sure if this is a complete list and if my color descriptions are correct, but it does cover alot of ground on the SUMO releases. If there are other reference codes that I missed, please don't hesitate to share with us. Thank you to Mr. Gabriel who was kind enough to share with me his horological knowledge.)


I've always been in love with the original Sumo. Ever since my purchase of the BLUMO as a sort of gift by the company I used to work with, I've always felt proud wearing it as a daily beater. It definitely was a watch that I could be proud of, especially as I hang out with Swiss watch fans. That is why when this SBDC001 became available, I did not hesitate to get it and it took 9 long months for it to reach my 7.5 inch wrist, but it was definitely worth the wait. Thank you to the kind seller, who, I believe got stuck outside the Philippine because of the Covid lockdown. Now, everytime I look at its dial and feel the watch on my wrist, I remember the last 14 years. I remember the first time it was first introduced by Seiko, and I think of the 25 new SUMOs (and counting) that were released since, which we can safely say that SEIKO's gamble definitely paid off and it was this watch that sits on my wrist right now that created all that ruckus.

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