Introducing Seiko Unveils the Marinemaster 1968 Heritage Diver and the JAMSTEC Limited Edition

Seiko’s journey in diver’s watchmaking began in 1965 with Japan’s first diver’s watch, which accompanied members of the Japanese Antarctic Research Expedition to the South Pole from 1966 to 1969. This pioneering model was followed in 1968 by the creation of the nation’s first 300m water-resistant diver’s watch. In the decades since, Seiko has continued to develop new technologies, designs, and features that have shaped its diver’s watches into what they are today.

Seiko’s collaboration with the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) began in the 1980s. In 1983, two professional diver’s watches rated to 600 meters were successfully tested aboard SHINKAI 2000, a manned research submersible operated by JAMSTEC.

Inspired by the spirit of bold exploration that unites JAMSTEC and Seiko, two new diver’s watches join Prospex’s flagship Marinemaster series. The first is a JAMSTEC collaboration, while the second is part of the permanent collection. Both are powered by Seiko’s self-winding Caliber 8L45 and represent the pinnacle of the brand’s diver’s watchmaking.

The Japan Agency for Marine-Earth Science and Technology (JAMSTEC) is a national institute dedicated to comprehensive marine research and development, advancing innovative science and technology.

The brand’s legacy of pushing the limits of the modern sports watch, while supporting marine research and conservation, continues through this longstanding partnership with JAMSTEC.

The cases both are crafted from stainless steel and, as with the previous generation, are fully treated with a super-hard coating. A notable evolution for this generation is the introduction of a ceramic bezel insert, available in polished black or blue depending on the edition. Both models measure 42.4mm in diameter with a thickness of 14.1mm. The case retains its characteristic interplay of brushed surfaces and pronounced polished bevels, along with deep notches on the bezel and crown. As expected, all elements are screw-down to ensure water resistance to 300 meters.

While the exterior follows the familiar contours of the 1968 diver’s watch—most notably its flowing silhouette and screw-down crown positioned at 4 o’clock—the construction has been enhanced for durability. The crown is not screwed directly into the case, but instead secured within a separate integrated component, allowing for easier servicing and replacement.

The black-dial model embodies the essence of the 1968 diver’s aesthetic, offering exceptional underwater legibility. Its deep black tone and fine-grain texture reduce light reflection, while the beveled edges of the indexes catch light from multiple angles to ensure optimal visibility.

The JAMSTEC collaboration model introduces a newly textured dial inspired by the trail left by an icebreaker moving through frozen seas—an evocative reference to Arctic exploration. Its vertically oriented blue gradient, deepening toward the center, is enhanced by a thick, transparent coating and polished finish, evoking the crystalline depths of the Arctic Ocean. The blue ceramic bezel further complements the dial while providing excellent scratch resistance.

Powering both watches is the automatic Caliber 8L45, representing the summit of Seiko’s mechanical expertise. The mainspring and hairspring are crafted from Spron, Seiko’s proprietary alloy. The movement delivers a power reserve of 72 hours, achieved through a long and slender mainspring, and operates within a daily tolerance of +10 to -5 seconds.

Both models are fitted with a three-link stainless steel bracelet, also treated with the brand’s super-hard coating. They feature an updated clasp system that allows for quick micro-adjustments of up to 16mm in 2mm increments via an internal sliding mechanism. Even when closed, the extension can be adjusted, ensuring ease of use and optimal comfort.

The two models will be available at Seiko boutiques and selected retailers worldwide from July 2026. The JAMSTEC collaboration edition will be limited to 1,000 pieces.

Prices start at EUR 3,800 (approximately AED 16,000) for the black dial model, and EUR 4,100 (approximately AED 17,350) for the limited edition.

For more information, visit Seiko’s official website.