SEIKO PROSPEX HBC005J1 SEA 145TH ANNIVERSARY LIMITED EDITION MEN WATCH

Seiko Prospex HBC005J1 — 145th Anniversary Limited Edition 1965 Heritage Diver's Watch

The Seiko Prospex HBC005J1 is the premium model in Seiko's second wave of 145th Anniversary Prospex limited editions — the 1965 Heritage Diver in Seiko Blue, limited to 4,000 pieces worldwide. Built on the 1965 Heritage platform that traces its design DNA directly to the 62MAS — Japan's first diver's watch, produced in 1965 — the HBC005J1 takes the iconic compact 40mm case and applies the 145th Anniversary Seiko Blue treatment: a blue aluminium unidirectional rotating bezel, a blue seconds hand, and a silver-white dial that creates the clean, cool, formally modern aesthetic that defines the entire 145th Anniversary series. At 4,000 pieces, it is more exclusive than the 9,999-piece HBB001K1, and more accessible than the 2,500-piece HAB004J1 Astron.

The specification is where the HBC005J1 separates itself decisively from the HBB001K1 sibling. The 6R55 calibre delivers +25/-15 seconds per day accuracy and a 72-hour power reserve — a full three-day reserve versus the HBB001K1's 41 hours. The curved sapphire crystal with anti-reflective coating on the inner surface replaces the Hardlex of the larger sibling with premium optical clarity and scratch resistance. And the water resistance rating is Diver's 300M — 50% deeper than the HBB001K1's 200M, and one of the highest ratings available in any 40mm steel dive watch in this price range. The three-fold clasp with secure lock, push-button release, and solid and slide adjuster completes a full professional diver's specification in the 1965 Heritage's compact and historically grounded case.

Key Features

• Seiko 6R55 automatic movement with manual winding and stop seconds — precise in-house mechanical performance
• Approx. 72-hour (3-day) power reserve — extended reliability for multi-day field and diving use
• Accuracy: +25/-15 seconds per day — superior to the 4R35 in the HBB001K1 sibling
• Diver's 300M water resistance — professional dive specification at the top of the 145th Anniversary range
• Silver-white dial — the clean, fresh 145th Anniversary Seiko Blue design language
• Seiko Blue accent on rotating bezel insert and seconds hand — signature anniversary colour, restrained and precise
• Blue aluminium unidirectional rotating bezel — purpose-built for safe and accurate dive timing
• Lumibrite on hands, indexes, AND bezel — complete low-light legibility for diving use
• Curved sapphire crystal with anti-reflective coating on inner surface — premium clarity and scratch resistance
• 40.0mm stainless steel case — compact 1965 Heritage proportions at 13.0mm slim / 46.4mm lug-to-lug
• Screw-down crown — water integrity protection for diving use
• Screw caseback with "LIMITED EDITION" inscription — provenance marked
• Three-fold clasp with secure lock, push-button release, and solid & slide adjuster — fully featured diver's clasp
• Magnetic resistance 4,800 A/m — protection in everyday and field environments
• Limited to 4,000 pieces worldwide — confirmed and meaningful scarcity

Why You'll Love It

The HBC005J1 is the 145th Anniversary Prospex for the collector who wants the best specification in the series. The 6R55 calibre, curved sapphire with AR coating, and Diver's 300M together represent a specification level that is rare in a 40mm stainless steel dive watch at this price point — and the 1965 Heritage platform brings a historical depth that the Samurai-cased HBB001K1 does not share in the same way. The 1965 Heritage case traces directly to the 62MAS — Japan's first dive watch — and that provenance gives the Seiko Blue anniversary treatment a more specific and historically grounded context: this is Seiko connecting its diving heritage to the brand colour that has defined its identity since the 1960s, in a case that began the dive watch story sixty years ago. At 4,000 pieces worldwide, it is exclusive without being unattainable.

HBC005J1 vs HBB001K1 — Which 145th Anniversary Prospex?

Both are 145th Anniversary Prospex divers in the Seiko Blue silver-white dial treatment. The HBC005J1 has a 6R55 calibre with 72-hour reserve, curved sapphire crystal with AR coating, and Diver's 300M water resistance, in a 40mm 1965 Heritage case — the more historically grounded, more specified, and more exclusive choice at 4,000 pieces. The HBB001K1 has a 4R35 calibre with 41-hour reserve, Hardlex crystal, and Diver's 200M in the updated 41.7mm Samurai case — the more affordable, more contemporary choice at 9,999 pieces. Same Seiko Blue 145th Anniversary aesthetic, two very different specifications and two very different design lineages.

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 62MAS — the Prospex dive line has stood for underwater precision and reliability. The HBC005J1 carries that sixty-year dive watch legacy and one hundred and forty-five years of brand heritage forward in the most specification-complete 145th Anniversary Prospex produced to date.

Backed by Seiko's official warranty. Authentic Seiko Prospex 145th Anniversary Limited Edition, sold by authorised retailer City Chain Singapore.

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