Seiko’s Most Extreme Dive Watch Gets a Celebratory Makeover

The deep-sea diving Prospex Marinemaster is getting a limited edition dial and impressive new movement.

the case and bezel of a steel dive watch

Published March 6, 2025

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Unfortunately, you can’t light candles at the bottom of the ocean.

So Seiko is celebrating the 60th birthday of the legendary 62MAS, the brand’s first true dive watch, with a trio of limited-edition Prospex Marinemaster references.

a steel Seiko dive watch with a blue dial and black bezel — Seiko’s 60th Anniversary Prospex Marinemaster is the the most extreme dive watch the brand has ever made.

The most impressive is, hands down, the reference SLA081J1, a 60th Anniversary Prospex Marinemaster equipped with Seiko’s newest and most advanced automatic movement and decorated with an engraved dial steeped in Japanese art history.

Already Seiko’s highest-performing dive watch, with a 600m dive rating vetted by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), this special edition Marinemaster now boasts a 72-hour power reserve.

The life aquatic

Over the past 60 years, Seiko has produced some of the best-performing dive watches of all time, along with a pantheon of approachable classics suited for casual diving and everyday wear.

a black dive watch — The Seiko Marinemaster lineage began in 1968 with the brand’s first “Professional” dive watch.

A heritage that illustrious should be celebrated with a watch that blows the rest out of the water, which is exactly what the 60th Anniversary Prospex Marinemaster does.

The hulking 16mm thick case, which measures 50.4mm lug-to-lug, is built from a single piece of titanium and has an L-shaped gasket that prevents helium infiltration during saturation diving, negating the need for an escape valve.

the case and bracelet locks pulled apart on a steel dive watch — The Prospex Marinemaster used an external clamp system to secure the bezel to the single-piece titanium case.

The stainless steel bezel is coated with a “diamond-like carbon” that makes it six times harder and more scratch-resistant than steel. To prevent weak spots, the bezel is secured in place with two external clamps, which screw into the back of the case.

Inside the case is Seiko’s newest 8L automatic movement series evolution, the 8L45. It boasts a 72-hour power reserve and an accuracy of +10 to -5 seconds per day. It is effectively a less decorated version of the movement found in Grand Seiko automatic watches outside of the Hi-Beat and Spring Drive lines.

Seiko

Seiko equipped this limited edition Marinemaster with a new curved-link stainless steel bracelet that is designed to contour to the wrist, and closes with a traditional three-piece clasp.

A shinkai dial

In a tradition borrowed from Grand Seiko, the dial on the 60th Anniversary Prospex Marinemaster is inspired by the natural aura of the deep ocean, known in Japanese as shinkai.

the dial and bezel of a Seiko Divemaster dive watch — The dial texture is based on Japanese *horimono* carvings.

The dial texture is based on horimono, a traditional Japanese woodworking and metal engraving technique, which is also used colloquially in reference to tattoo art.

Horimono creates very shallow reliefs that appear to have great depth by utilizing light and forced perspective on a miniature scale. It is an art form with a strong cultural heritage and significance in Japan.

The dial of this limited-edition Marinemaster is only a couple of millimeters thick but creates the appearance of rolling waves over a dark ocean. A clear coating enhanced the effect with a lustrous finish.

To prevent the hour markers from coming loose, they are set into the dial rather than applied on top. The hour and minute hands have a new design for the Marinemaster line with flat tops, beveled off at the edges, and rounded lume inserts.

The 60th Anniversary Prospex Marinemaster may look like just another classic, beautiful dive watch fit for everyday wear. But there is nowhere on or below the surface of planet Earth where this watch can’t go.

Availability and pricing

Seiko’s 60th Anniversary Prospex Marinemaster, reference SLA079J1, will be released in July 2025. The limited edition of only 600 units will be sold exclusively at Seiko boutiques and through a very select group of authorized dealers for $4,600.