Prospex 200M Sumo Gradient Grey Sapphire 3rd Gen Ref. SBDC177

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 Gradient Grey Sapphire 3rd Gen Ref. SBDC177 / SPB323

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 2022, Seiko has added more high-end materials to its latest edition. Today we introduce the Seiko Prospex 200m Sumo Gradient Grey Sapphire 3rd Gen Ref. SBDC177.

New Seiko Calibre 6R35 With 70 Hours Power Reserve

True to the Sumo legacy, this watch retains the oversized dimensions of the original Sumo. It has a 45mm diameter, a 12.9mm height and a lug-to-lug measurement exceeding 52mm.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.

Iconic Sumo Case Design

A mixture of satin brush and Seiko high polishing on the sides is observable on the entire timepiece, particularly around the lugs. Run by Seiko’s latest automatic caliber, 6R35, which is an upgrade from the workhorse 6R15, the watch operates at 21,600 BPH (3 Hertz) together with hacking and hand winding capabilities. The watch has 24 jewels and a superior power reserve of 70 hours.

Seiko's LumiBrite

Besides, the trademark “Sumo Belt” index at 12 o’clock is still part of this new watch and the original shape of the handset. All elements are generously topped with Lumibrite, with a new small luminous marker next to the date window, for better readability. The dials now have a gradient effect over a muted grey background with a fine horizontal wave pattern, displaying understated elegance. The 3-link bracelet, comprising steel with Super-Hard coating, is now totally brushed and has a new, robust folding clasp with a secure lock, push-button release and wetsuit extension.

Overall, this dive watch with its grey monotone colorway and excellent build quality displays Seiko’s efforts to enhance the overall quality and resistance of its Sumo watch collection and merits a purchase.