SEIKO PROSPEX SPB321J1 2022 SUMO DIVER AUTOMATIC MEN WATCH

Seiko Prospex SPB321J1 — Sumo Automatic Diver's Watch

The Seiko Prospex SPB321J1 is the 2022 Sumo — a meaningful upgrade of one of the most beloved case shapes in the Seiko Prospex lineup, bringing ceramic bezel, super-hard coating on the case and bracelet, and a new 3-row bracelet to the Sumo specification for the first time. The blue ceramic unidirectional rotating bezel with Lumibrite coating on its markings is the standout addition: the 2022 Sumo is the first Sumo to bring Lumibrite to the bezel itself, meaning the dive timing reference is readable in the same low-light conditions that demand the watch in the first place. The blue gradation dial with its fine pressed wave pattern gives it an ocean-connected visual depth that the earlier Sumo dials do not share.

Powered by the in-house 6R35 automatic calibre with hand-winding capability and a 70-hour power reserve, the SPB321J1 delivers the full professional diver's specification — Diver's 200M water resistance, screw-down crown, and the ceramic unidirectional bezel — in a 45mm super-hard coated case at 13.4mm slim. The sapphire crystal with anti-reflective coating on the inner surface protects the dial with excellent optical clarity in all light conditions, and the three-fold clasp with diver's extension makes it genuinely practical for suit-to-wetsuit use.

Key Features

• Seiko 6R35 automatic movement with manual winding — self-winding with the convenience of hand-winding when needed
• Approx. 70-hour power reserve — dependable performance through an extended weekend without wearing
• Accuracy: +25/-15 seconds per day — dependable automatic timekeeping
• Diver's 200M water resistance — built for recreational diving and water sports
• Blue gradation dial with pressed wave pattern and baton markers — ocean-connected depth that distinguishes the 2022 Sumo from its predecessors
• Lumibrite on hands, indexes, and bezel — full Lumibrite coverage including the bezel for complete low-light dive timing legibility
• Blue ceramic unidirectional rotating bezel — scratch-resistant, precise, and purpose-built for dive timing
• Sapphire crystal with anti-reflective coating on inner surface — premium clarity and scratch resistance in all light conditions
• 45mm stainless steel case with super-hard coating — Sumo proportions at 13.4mm slim profile
• Screw-down crown — water integrity protection for diving use
• Screw caseback — secure construction with serial designation
• Date display — everyday practicality built in
• Stainless steel 3-row bracelet with super-hard coating — new for 2022, with three-fold clasp and diver's extension

Why You'll Love It

The SPB321J1 is the Sumo for the buyer who wants the best Sumo — not just the iconic case shape, but the full 2022 upgrade package that brings it level with the materials and finishing expected of a watch at this price. The blue ceramic bezel with Lumibrite is the headline change: dive timing with complete legibility in the dark is now possible without compromising the watch's specification. The wave-pattern gradation dial gives it a visual sophistication that flat-colour dials cannot replicate. The super-hard coating on case and bracelet keeps it looking new through active daily use. And the 3-row bracelet with diver's extension is a practical upgrade that makes the watch more wearable — more easily — in the environments it was designed for.

The Seiko Prospex Story

Prospex is a combination of the words "Professional" and "Specifications." Seiko Prospex timepieces are designed to be practical, reliable, and durable — built to meet the high standards required in extreme environments for sports lovers and adventure seekers alike. The story begins in 1881, when Kintaro Hattori founded a clock and watch shop in Ginza, Tokyo — the business that would become the Seiko of today. Since 1965, when Seiko created Japan's first diver's watch, the Prospex dive line has stood for underwater precision and reliability. The SPB321J1 carries that sixty-year legacy forward in the most materially refined expression of the Sumo case to date.

Backed by Seiko's official warranty. Authentic Seiko Prospex watch, sold by authorised retailer City Chain Singapore.

Explore the full Seiko Prospex Collection or browse all Seiko watches at City Chain Singapore.