March 18 2026

A New Chapter For The Marinemaster: Seiko Introduces HBF001 And HBF002

Ricardo Amaral NEW RELEASES, SEIKO 2026, Diver, JAMSTEC, Limited Edition 0

Seiko expands its professional dive watch portfolio with the introduction of two new Marinemaster models: the Prospex Marinemaster 1968 Heritage Diver HBF001 and the JAMSTEC Limited Edition HBF002. Both references build on the brand’s long-standing expertise in underwater timekeeping, combining historical design cues with modern technical upgrades.

A Modern Evolution of a Historic Diver

The Marinemaster name has consistently been associated with high-performance dive watches within Seiko’s lineup. These new models continue that tradition, drawing inspiration from the 1968 Hi-Beat 300m Diver (ref. 6159-7001), a milestone in Japanese dive watch engineering.

This latest generation refines the design introduced in recent Marinemaster releases, maintaining the recognizable silhouette while introducing improvements in durability, ergonomics, and mechanical performance.

Case and Construction

Both the HBF001 and HBF002 are housed in a stainless steel case measuring 42.60 mm in diameter, with a lug-to-lug distance of 49.30 mm and a thickness of just over 14 mm. The increase in thickness compared to previous models is mainly due to the updated movement and caseback construction. Water resistance is rated at 300 meters, aligning with professional diving standards.

The case design remains faithful to the 1968-inspired architecture, featuring a combination of brushed surfaces and polished bevels that enhance both aesthetics and durability. The screw-down crown is positioned at 4 o’clock, a signature Seiko design choice that improves comfort on the wrist, while the bezel incorporates deep notches to ensure a secure grip even in challenging conditions.

To improve resistance against scratches and wear, Seiko applies a super-hard coating to both the case and bracelet. A notable upgrade for this generation is the addition of a ceramic bezel insert, available in black or blue depending on the model. Protecting the dial is a dual-curved sapphire crystal with an anti-reflective coating, ensuring optimal legibility in different lighting environments.

Dial Variations: Classic vs Experimental

The HBF001 adopts a traditional diver’s watch aesthetic, featuring a black ceramic bezel paired with a subtly textured black dial designed to minimize light reflection. The applied hour markers and hands are generously filled with LumiBrite to ensure strong visibility in low-light conditions. The date display has been repositioned to 3 o’clock for a more conventional layout, accompanied by a small luminous marker to maintain balance and readability.

In contrast, the HBF002 offers a more distinctive visual identity. Developed in collaboration with the JAMSTEC, this limited edition of 1,000 pieces introduces a dial inspired by polar exploration. The surface features a pronounced texture that evokes the path of an icebreaker cutting through frozen seas, combined with a vertical gradient that transitions from ice white at the top to deep ocean blue at the bottom. A glossy coating enhances the sense of depth, while details such as the gold-colored seconds hand and white minute flange add contrast. The date window is also framed, giving it a more defined presence on the dial.

Movement: Calibre 8L45

Inside both models is the automatic Calibre 8L45, representing a significant technical upgrade for the Marinemaster collection. This movement is derived from the architecture of Grand Seiko’s 9S65 calibre, bringing higher performance standards to the Prospex range.

The power reserve has been extended to approximately 72 hours, allowing the watch to run for three days without winding. Accuracy is rated between +10 and -5 seconds per day, reflecting improved precision compared to previous calibres. The movement has also been engineered with enhanced shock resistance, making it more suitable for demanding environments. In terms of finishing, the calibre features striped decoration across the bridges and rotor, reinforcing its position in the upper tier of Seiko’s mechanical offerings.

Bracelet and Clasp System

The watches are fitted with a three-link stainless steel bracelet that continues the robust design language of the case. A newly developed folding clasp introduces a practical micro-adjustment system, allowing the wearer to extend or reduce the bracelet length by up to 16mm. Adjustments can be made in 2 mm increments through a sliding mechanism, making it easier to adapt the fit in real time, whether worn directly on the wrist or over diving equipment.

Availability and Pricing

The HBF001 joins the permanent collection and is priced at € 3,800, while the HBF002 is released as a limited edition of 1,000 pieces with a retail price of € 4,100. Both models sit near the top of the Prospex lineup, positioned just below the brand’s full professional-grade titanium Marinemaster models.

Final Thoughts

With these new releases, Seiko continues to refine the Marinemaster concept by combining heritage-driven design with practical upgrades. The introduction of a new movement, improved materials such as the ceramic bezel, and an enhanced clasp system demonstrate a clear focus on performance and usability. At the same time, the availability of both a classic and a more experimental design ensures that the collection appeals to a wide range of enthusiasts.