Seiko Prospex 1968 Heritage Diver GMT automatic blue dial steel bracelet 42 mm

Heritage & Collection

The year 1968 marks a pivotal milestone in Seiko’s history and in the global watch industry: the introduction of Japan’s first professional diver’s watch with 300 meters of water resistance, powered by a Hi-Beat caliber. With its robust case, screw-down crown at 4 o’clock, and proven field reliability, this model laid the foundation for a design language and technical expertise that continue to inspire the Prospex collection today.

In 2025, to celebrate 60 years of Seiko divers, the Japanese brand unveiled several anniversary creations, among them the SPB509, a 1968 Heritage Diver GMT designed as a modern tribute. Produced in a limited run of 6,000 pieces, it blends the historic DNA of the 1968 Diver with contemporary technologies, affirming its legitimacy both as a heritage piece and as a functional dive tool.

This anniversary version stands out not only with its reinforced 300-meter water resistance — a significant improvement over the standard 200 m models — but also with its unique wave-pattern embossed dial. This symbolic motif, directly inspired by the emblem engraved for decades on Prospex Diver’s casebacks, evokes the ocean and underlines the mission of the SPB509: a tool engineered for underwater exploration, yet versatile enough to serve travelers thanks to its GMT function.

Through this creation, Seiko does more than commemorate its past: it demonstrates its ability to evolve icons while staying true to their original spirit. The SPB509 embodies the best of both worlds: historical fidelity and contemporary innovation.

Design & Aesthetics

The SPB509 inherits the iconic architecture of the 1968 Diver, recognizable by its angular case, broad shoulders, and screw-down crown at 4 o’clock. Measuring 42 mm in diameter, 13.3 mm in thickness, and 48.6 mm lug-to-lug, it maintains a strong wrist presence while remaining well-balanced. A major update is its hardened stainless steel case, now water-resistant to 300 meters. This improvement required a thicker caseback and reinforced sapphire crystal, while preserving overall ergonomics.

The unidirectional bezel features a blue ceramic insert with a crisp white 60-minute scale and a luminous pearl at 12 o’clock. This aesthetic choice highlights both the professional nature of the watch and its anchoring in Seiko’s marine heritage. Alternating polished and brushed surfaces create subtle plays of light, reinforcing its premium character.

The dial is the centerpiece of this anniversary edition. Rendered in deep blue and embossed with a wave motif, it directly recalls the historic Prospex Diver’s emblem inspired by the sea. Applied indexes integrated into the relief are coated with white LumiBrite, ensuring perfect readability in all conditions. Faceted hands, also luminescent, stand out clearly against the textured backdrop.

The GMT function adds a practical dimension. A prominent golden central hand points to a 24-hour scale printed on the inner flange, allowing tracking of a second time zone.

The watch is protected by a domed sapphire crystal with inner anti-reflective coating, ensuring flawless legibility. Its stainless steel bracelet with brushed and polished links is equipped with the new 2025 clasp: a folding buckle with a micro-adjustment system offering 15 mm of on-the-fly adjustment in six 2.5 mm steps, for a perfect fit on the wrist or over a wetsuit.

The SPB509 thus combines robustness, elegance, and practicality. It successfully preserves the bold and professional spirit of the 1968 Diver while incorporating modern and exclusive refinements, reinforcing its status as an anniversary model.

Movement & Performance

At the heart of the SPB509 beats the automatic Caliber 6R54, Seiko’s latest-generation movement, building on the 6R55 while adding a GMT complication. Beating at 21,600 vibrations per hour (3 Hz) with 24 jewels, it provides a comfortable 72-hour power reserve — three full days. This autonomy ensures the watch remains running even after a long weekend off the wrist, a practical benefit for mechanical watch enthusiasts.

The 6R54 features an “office GMT” function: the 24-hour hand is independently adjustable, allowing tracking of a second time zone without disturbing the main time display. While different from a “true GMT” with an independently adjustable local hour hand, this configuration remains extremely useful for daily use, particularly for monitoring a reference time zone during travel or international communication.

Beyond this practical complication, the movement offers the essential functions expected from a professional diver: hours, minutes, seconds, and a date at 4:30. The hacking seconds feature allows precise time-setting, while manual winding complements automatic winding via the bidirectional rotor.

Seiko specifies an accuracy of –15 to +25 seconds per day, a realistic tolerance for this caliber, which often performs more stably in practice. Robustness is further ensured by 4,800 A/m magnetic resistance, protecting the watch from everyday electromagnetic fields (smartphones, laptops, speakers, etc.).

Finally, the upgraded 300-meter water resistance confirms the professional-grade status of this anniversary edition. It positions the SPB509 among divers capable of serving both underwater exploration and international travel, embodying the Prospex philosophy: Professional Specifications.

A limited edition of 6,000 pieces

The Seiko Prospex 1968 Heritage Diver GMT SPB509 is part of the celebrations for the 60th anniversary of Seiko’s first dive watch, the 1965 62MAS. With this limited edition of 6,000 pieces worldwide, Seiko goes beyond a simple homage, offering a GMT diver that blends commemorative aesthetics, technical innovations, and professional-grade reliability.

Its blue wave-pattern embossed dial, inspired by the historic emblem engraved on Prospex Diver’s casebacks, immediately calls back to the brand’s marine legacy. This strong visual identity, combined with a blue ceramic bezel and contrasting golden GMT hand, gives the watch a character that is both sporty and elegant, instantly recognizable among contemporary models.

Each piece is individually numbered and engraved with “Limited Edition” on the caseback, reinforcing its exclusivity and collector appeal. In addition, the latest-generation steel bracelet with its newly introduced micro-adjust clasp (offering up to 15 mm adjustment in 2.5 mm steps) reflects Seiko’s commitment to comfort and ergonomics in both daily wear and diving use.

Priced at €1,900, the SPB509 positions itself as a highly desirable anniversary diver, both accessible and rich in technical content. It will appeal to watch enthusiasts drawn to the great narratives of Japanese diving history, as well as travelers and tool-watch lovers seeking a robust, reliable diver equipped with a second time zone.

More than a watch, the SPB509 is a contemporary collectible, embodying the continuity between Seiko’s glorious past and its future in dive watchmaking.