Seiko Sumo

Since its inception in 2007, Seiko's Sumo collection has included some of the most popular, high-quality, and affordable diving watches on the market. As the name implies, these watches are comparatively large, like the famous Japanese wrestlers. But while the timepieces measure some 45 mm across, they're also relatively thin, and thus don't have an excessively large overall look.

A characteristic feature of the Sumo is its unidirectional diving bezel, which is set into the case. This design element is partly responsible for the relatively slim profile of the watch. Along with the timepiece's diameter, the position of the crown at 4 o'clock is another typical feature of the three-hand Seiko Sumo.

Every three-hand Sumo variant is powered by the automatic in-house caliber 6R15 or 6R35. While the former has a power reserve of 50 hours, the latter boasts some 70 hours. In addition to the automatic Sumo models, a solar-powered chronograph is also available. All Sumo editions are made of stainless steel (some references have a black coating) and are water-resistant to 200 m (20 bar, 656 ft).

Within the Prospex collection – the name stems from "Professional Specifications" – the Seiko Sumo falls in the middle range of prices. It is a bit more expensive than the Turtle, but considerably less expensive than the Marinemaster.

A standard edition Seiko Sumo like the ref. SBDC033, fitted with the caliber 6R15 and a Hardlex crystal, costs about 400 USD. Mid-range Sumo models like the limited edition ref. SZSC004, which comes with the more modern caliber 6R35, a jade-green dial, and green bezel, change hands for approximately 860 USD.

Weighing in at around 1,000 USD is the limited edition Seiko Sumo PADI ref. SBDC049, of which there were only 1,000 made. To celebrate the 50th anniversary of their diving watch, Seiko released a number of limited editions in 2015, including the Sumo ref. SBDC027, limited to 2,000 pieces. This watch is particularly popular among collectors and demands an investment of around 1,700 USD, making it the most expensive three-hand Sumo diving watch. Significantly more affordable than the rare three-hand Sumos are solar-powered Sumo chronographs such as the ref. SSC795J1. The price point for this timepiece sits at about 650 USD.

The case of the Seiko Sumo is finished to a high standard and can easily hold its own against Swiss luxury watches. It is superbly polished and satin brushed. Even the in-house movements 6R15 and 6R35 have a fine finish, despite being hidden behind a massive, screw-down case back. Thanks to this case back and the screw-down crown, the watch is water-resistant to 200 m (20 bar, 656 ft). The fluted crown is easy to use, as is the unidirectional diving bezel, which for safety reasons can only be turned counterclockwise.

Stainless steel models like the SBDC031 and SBDC033 are available with a black or blue dial and matching bezel inlay and cost approximately 400 and 460 USD, respectively.

The reference SPB125J1 features a case and bracelet completely coated in black DLC and an orange second hand. This model also comes with a sapphire crystal and is limited to 7,000 pieces. Furthermore, each piece is numbered, with the number printed on the case back. Powered by the caliber 6R35, this timepiece costs approximately 790 USD in mint condition.

Seiko presented the ref. SPB181J1 in cooperation with the world's leading training organization for divers, PADI (Professional Association of Diving Instructors). This model features a blue and red Pepsi bezel and a red second hand, and is powered by the caliber 6R35. In contrast to the standard Sumo editions, the Sumo PADI has a sapphire crystal. This watch changes hands for a little over 700 USD.

The 50th Anniversary Seiko Sumo SBDC027

In comparison to standard Sumo models, the 50th anniversary edition has a number of upgrades that increase its overall value. Instead of the usual Hardlex glass, the SBDC027 features a scratch-resistant sapphire crystal to provide a clear view of the dial, and the case has a DIASHIELD coating to protect it from minor scratches.

The bezel design is more reminiscent of that of the Marinemaster 300 (ref. SBDX001). The shape of the hands and hour markers are also different. The latter are bar indices rather than large dots, and the rod-shaped hands are notably more slender than the sword hands on standard models. At its debut in 2015, the Sumo SBDC027's sold for around 1,000 USD; you can buy this watch on Chrono24 for approximately 1,800 USD in mint condition.

For some Seiko Sumo fans, a solar-powered chronograph may not quite fit the image we associate with the typical Sumo diving watch. However, the timepiece's characteristic case design with a recessed bezel heralds its indisputable place in the Sumo line.

Take the refs. SSC795J1 and SSC761J1, for example, both of which measure 44.5 mm in diameter. The case and the bracelet of the former model are made of satin-brushed stainless steel. As is common with almost all Sumo watches, the dial features luminous dot indices that, on the chronograph, are interrupted by subdials at 3, 6, and 9 o'clock and bar indices.

The chronograph is fitted with the solar caliber V192, which draws its energy from sunlight. According to Seiko, this caliber has an average deviation of +/- 15 seconds per month. You can buy this model with a blue and red Pepsi bezel for around 660 USD in mint condition.

The reference SSC761J1 is technically identical to the Pepsi version, but as part of the Black series it's completely black. This watch also features a red minute hand and cream-colored LumiBrite. Instead of a steel bracelet, the timepiece comes on a silicone strap with a stainless steel pin buckle. In mint condition, this watch demands an investment of about 680 USD on Chrono24.