Prospex 200M Sumo GMT The Black Series Ref. SBPK007

The nickname Sumo was initially not the official name of this Prospex series of watches. Yet somehow the name stuck and is now acknowledged by Seiko itself. The name's origins could be explained by some theories. The first theory is that of the robust, oversized countenance of the watch together with a thin 20mm bracelet. The second explanation lies in how the 12 o'clock marker looks like a Mawashi, the underwear donned by Japanese sumo wrestlers during a match. The third explanation lies in how the bezel's shape is akin to the Dohyo or ring where Sumo takes place.

Seiko Prospex 200M Sumo GMT The Black Series Ref. SBPK007

Launched in 2007, the Seiko Sumo was presented under the reference Prospex Diver 200m SBDC031 as a mid-range offer, above the entry-level Turtle and Samurai. This year once again in 2023, Seiko has added more high-end materials to its latest edition, and now with a traveller's GMT function. Today we introduce the Seiko Prospex 200M Sumo Solar Black Series GMT Ref. SBPK007.

True to the Sumo legacy, this watch retains the oversized dimensions of the original Sumo. It has a 45mm diameter, a 13.2mm height and a lug-to-lug measurement exceeding 51.8mm. The overall shape of the watch also resembles its predecessors, with the same twisted lugs and curved profile, alternating polished bevels and brushed lines. The 4 o'clock crown and the watch will resonate with watch owners of its predecessors. The sapphire crystal, screw-down caseback and crown and 200m water-resistance are also intact. Stainless steel with Super-Hard coating forms the material of this watch, making it more resistant to wear and tear. Besides, the 200m water resistant Sumo stainless steel case showcases Seiko's beautiful handiwork and artistry.

Seiko Calibre 5K65

Besides, the trademark "Sumo Belt" index at 12 o'clock is still part of this new watch and the original shape of the handset. Now, it even comes with a white GMT hand that contrasts the black of the watch which allows wearer to read off a 24-hour format of a second timezone. All elements are generously topped with Lumibrite, with a new small luminous marker next to the date window, for better readability. The dial now has a two-tone black and white chapter ring to assist the second time-zone reading, flanking a muted black background, displaying understated elegance. The 20mm 3-link bracelet, comprising 316L non-corrosive steel, is now totally brushed and has a new, robust folding clasp with a secure lock, push-button release.

Run by Seiko's latest solar caliber, 5K65, which is an utmost reliable and practical GMT movement. Apart for the quick adjustment of the GMT hand, the movement provides approximately 9 months of power reserve when it is fully charge, in tandem of an accuracy of +- 15 seconds monthly. Further provides both overcharge prevention and instant start function, while having indication of low power reserve with its jumping second hand. Now, isn't this a perfect diver watch which you do not have to worry on winding up the watch frequently?

Seiko's LumiBrite

Overall, this all-new GMT watch with its Sumo case clads excellent build quality. It displays Seiko's efforts to enhance the overall quality and complication of its Sumo watch collection and merits a purchase for any watch enthusiasts who seek a grab-and-go watch which reads multiple timezones, on land and deep underwater.