Seiko Prospex has announced the "Marinemaster 1968 Heritage JAMSTEC Collaboration Limited Edition" in collaboration with the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), with whom it has had a cooperative relationship since the 1980s. Inspired by Seiko's diver's watch from 1968, the case design, including its streamlined shape and crown at the 4 o'clock position, has been retained. A regular model sharing the same basic design was also announced simultaneously.
Seiko unveils limited edition Marinemaster model inspired by a 1968 diver's watch.
Seiko Prospex has announced the "Marinemaster 1968 Heritage JAMSTEC Collaboration Limited Edition" diver's watch, a limited edition model created in collaboration with the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), as well as a regular model that shares the same basic design. The "1968 Heritage" model name indicates that it is inspired by the 1968 model, and its streamlined form and crown at the 4 o'clock position are iconic features that have been inherited.
Automatic movement (Cal. 8L45). 35 jewels. 28,800 vibrations/hour. Power reserve of approximately 72 hours. Stainless steel case (42.6mm diameter, 14.1mm thickness). 300m water resistance. Limited edition of 1000 pieces worldwide (250 pieces in Japan). 550,000 yen (tax included). Scheduled for release on July 10, 2026 (Friday).
Seiko's history of diver's watches began in 1965, and from the following year, they were adopted four times as equipment for the Japanese Antarctic Research Expedition's wintering team. The 1968 model, which served as the inspiration for the 1968 Heritage, was a 300m water-resistant diver's watch equipped with a world-class 10 vibrations per second high-beat movement. The streamlined form and crown at the 4 o'clock position adopted in this model had a major influence on subsequent Seiko diver's watch designs.
Since then, Seiko has continued to improve its technology to tackle extreme environments, such as releasing the world's first 600m saturation diving model using titanium in 1975.
Since the 1980s, Seiko has built a collaborative relationship with JAMSTEC. Utilizing various opportunities, such as deep-sea testing of saturation diving models aboard the manned submersible "Shinkai 2000" in 1983, Seiko has continued to push the boundaries of sports watches.
Furthermore, Seiko supports JAMSTEC with a portion of its sales, and from 2025, it will newly begin supporting JAMSTEC's Arctic research. With gratitude for the vast ocean, Seiko is contributing to environmental protection through marine research.
The Marinemaster 1968 Heritage JAMSTEC Collaboration Limited Edition model features a dial design inspired by JAMSTEC's recent activities. The design evokes the image of an icebreaker navigating icy seas, symbolizing how Arctic research is paving the way for Japan's future. A newly developed, three-dimensional stamped pattern, reminiscent of sea routes etched into sea ice, has been incorporated. The deepening blue gradient towards the center, combined with the depth created by carefully polishing a thick layer of transparent paint, expresses the clear, deep waters of the Arctic Ocean. The bezel insert is made of blue ceramic, color-coordinated with the dial and boasting a glossy finish for superior aesthetics. Its high scratch resistance is another attractive feature. The case, with its iconic streamlined shape and crown at the 4 o'clock position, is water-resistant to 300 meters, suitable for air diving.
A regular model featuring the classic black color is also available.
Automatic movement (Cal. 8L45). 35 jewels. 28,800 vibrations/hour. Power reserve approximately 72 hours. Stainless steel case (42.6mm diameter, 14.1mm thickness). 300m water resistance. 506,000 yen (tax included). Scheduled for release on July 10, 2026 (Friday).
A regular model sharing the same basic design elements as the Marine Master 1968 Heritage JAMSTEC collaboration limited edition, including the case shape, bezel, indices, and hands, was also announced at the same time.
The color is black, a classic choice for diver's watches. The base of the dial has a textured finish, creating a matte and expressive texture while preventing reflections and ensuring good visibility.
Equipped with the Cal.8L45 movement, which offers a practical power reserve and high precision.
Both models are equipped with the Cal.8L45 automatic movement. By improving the shape and design of the mainspring to stabilize the energy output and performing rigorous precision adjustments during assembly, it achieves both a power reserve of approximately 72 hours and stable accuracy of +10 to -5 seconds per day. This performance provides a sense of reliability that supports users not only in the marine environment where diver's watches are used, but also in active lifestyles and business settings.
The buckle features a newly developed adjuster, allowing for bracelet size adjustment.
Both models also feature a newly developed one-push diver adjuster system for the buckle. This system allows for eight length adjustments of approximately 2mm increments, with a maximum adjustment range of approximately 16mm, and these adjustments can be easily made with a button. It is also noteworthy that the length can be shortened while the buckle is closed, making fine adjustments easy.
This system, which allows for easy and precise length adjustment, is appealing because it can accommodate changes in wrist size not only during diving but also in daily life, ensuring a consistently comfortable fit.
