Most watch reviews that I have read start off with a story of the author’s inspiration behind getting the watch. Something in their childhood that spurred them to make the purchase, or some cool reasons that prompted them to eventually take steps to acquire said watch. For my Seiko Sumo Prospex Black Series SPB125J1, there will be no such introduction.

My thought process was simple. Having already checked the ‘steel bracelet’ and ‘leather strap’ look with two of my prior watch purchases, my next watch was always going to be a rugged, no-nonsense diver that can also look the part, and that is where the Seiko Sumo Black comes in.

Seiko introduced the SPB125J1 back in 2020, as part of a trio of Seiko’s Black Series Limited Edition watches. While technically it is a limited edition, the large quantity of 7,000 pieces makes this not so ‘limited’ in my opinion (not that it bothers me). The Seiko Sumo Black has black hard-coating on its stainless steel case, black/grey bezel, cream-colored hour markers encircled by silver outlines, as well as a sexy orange color outlining the minute hand. The in-house automatic caliber 6R35 movement is sandwiched by a covered case back, as well as a sapphire crystal with anti-reflective coating on the inner surface. The color combination of predominantly black, orange and white is unique, and the large and tidy hands circling the black dial makes the Sumo a very handsome and masculine watch.

What this means is that I can treat the Seiko Sumo Black as a proper tool watch, wearing it whenever I am engaging in any outdoor activities like swimming in the pool (or sea), or even playing non-contact sports (cue the visualization of Rafael Nadal wearing his Richard Mille while playing tennis). With the Sumo, I am less inclined to worry about scratching the watch due to the black hard-coating and sapphire crystal. Hence, the Sumo is my go-to watch whenever I anticipate being out under the sun and perspiring plenty, and also because I cannot imagine putting my higher-end Swiss dive watch through the same rigors. Admittedly, my Omega SMP 300 diver has more visible scratch marks than my Sumo (yet to see any) even though the Sumo has been in my collection longer.

The Seiko Sumo Prospex Black Series SPB125J1 has a 45mm case and wears a little smaller due to the black case and strap. The silicone strap is very comfortable to wear and allows for ventilation due to the cleverly designed wavy shape of the strap near the lugs. After wearing it and exposing it to the elements though, the silicone strap has started to become a little sticky, and this is the one gripe I have with this watch. However, this can be easily resolved by switching out the OEM strap with an FKM rubber strap.

So, would I recommend others to get the Seiko Sumo Black? That would depend on what you have in your existing collection. For me, the SPB125J1 would only be part of one’s collection, due to its lack of versatility. This is not a watch I would wear to any formal occasions, or as part of my office attire. If you want a Sumo that is more versatile, take a look at the SPB101J1 (black bezel and dial, with silver case and bracelet), or the SPB103J1 (green bezel and dial, with silver case and bracelet).

The Seiko Sumo Prospex Black Series SPB125J1 works for me because it has a cleaner and larger look than the Seiko Turtle or Samurai, and is not as aggressive or as chunky as the Seiko Monster and Tuna respectively. It has the right balance of size, legibility, and style that suits my personality. Most importantly, the Seiko Sumo Black plays the tool watch role for me very well, a role that I do not see other watches in my collection undertaking.