Seiko’s dive watch story begins in 1965 with the introduction of the “62MAS” — Japan’s very first diver’s watch. It came equipped with an automatic movement and could handle depths up to 150 meters. This was not just a desk diver; it was field-tested during the 8th Japanese Antarctic Research Expedition, so durability was more than just marketing.

In 1968, Seiko released Japan’s first high-beat automatic movement, which significantly improved accuracy and performance, incorporating this milestone caliber into their landmark 1968 Diver’s Watch. By 1975, they unveiled the world’s first titanium diver’s watch, offering serious corrosion resistance and a lighter case — basically, a win for anyone spending time underwater.

Seiko 62MAS, a professional diver’s watch from 1965

To commemorate sixty years of diving heritage, Seiko launched three limited-edition Prospex models: the Marinemaster Professional SLA081, the 1968 Heritage Diver’s GMT SPB509, and the 1965 Heritage Diver’s Watch SPB511. Each model draws from Seiko’s historic design language, but with modern technology — think superior chronometry, greater depth rating, and improved case construction. Bottom line: they’re a nod to the original divers, but ready for today’s technical demands.

Prospex Marinemaster Professional 60th Anniversary

Inspired by the profile of Seiko’s landmark 1968 creation, SLA081 is a professional diver’s watch with a one-piece titanium case measuring 45.4mm in diameter and is designed to withstand the rigors of saturation diving with a water resistance of 600 meters. The case is coated with Seiko’s proprietary super-hard coating to provide enhanced scratch resistance. While the SLA081 is a substantial diver, the lightweight titanium makes it comfortable to wear for either desk diving or professional diving. Seiko’s L-shaped gasket is used for sealing the case, eliminating the need for a helium escape valve.

Seiko Prospex Marinemaster Professional Diver’s 60th Anniversary Limited Edition

For the insert inside the unidirectional rotating elapsed timing bezel, Seiko opted for stainless steel with DLC coating to make it almost six times more scratch resistant. The bezel is secured by black coated elements between the lugs that are screwed in through the caseback allowing for a seamless transition and a more streamlined profile.

Seiko states that the gradient blue dial of the SLA081 is designed to resemble the ocean’s deep hues, with the color darkening towards the edges. The dial features a textured wave pattern and is coated with a layer of clear lacquer to enhance its luster. The embossed hour markers and the large, faceted hands are coated with Seiko’s proprietary LumiBrite material that provides excellent legibility in low-light conditions. The date window at 3 o’clock blends seamlessly into the dial landscape, allowing the markers and hands to be the focal points of the dial.

Powering the SLA081 is a new 8L45 movement, developed with the ability to withstand harsh diving conditions. This impressive new caliber incorporates the semiconductor MEMS (Micro Electro Mechanical System) technology in the production of the escapement, allowing for the creation of components that are lighter and more precise. The movement also has a reversing gear train system for bi-directional winding.

The titanium bracelet features rounded links for comfort during both underwater adventures and daily wear. The clasp is equipped with a push-button release, a secure lock, and a slide adjuster, making for a snug fit even when it is worn over a diving suit.

As an anniversary model, the SLA081 is limited to 600 pieces. While some may argue a price just north of USD 4,500, the SLA081 justifies its cost with its exceptional build, features, and chronometry.

Tech Specs: Seiko Prospex Marinemaster Professional Diver’s 60th Anniversary Limited Edition

Reference: SLA081
Movement: Self-winding Caliber 8L45; 72-hour power reserve
Functions: Hours and minutes; central seconds; date
Case: 45.4mm × 16mm; titanium; rotating bezel with DLC coating; water-resistant to 600M
Dial: Gradient blue with pressed pattern; hour markers and hands with LumiBrite
Strap: Titanium bracelet on three-fold clasp with secure lock and slide adjuster
Price: USD 4,600 / €5,200
Availability: Limited to 600 pieces

Prospex 1968 Heritage 60th Anniversary GMT Diver

The SPB509 also pays homage to Seiko’s 6159-7001 dive watch from 1968, which was known for its distinctive design and 300m water resistance. While the design is reminiscent of the original model, it includes modern features such as a ceramic bezel insert and sapphire crystal. The SPB509 also includes a GMT complication, making it a more versatile dive watch.

Seiko 6215-7000 from 1968

The stainless steel case measures 42mm in diameter and is 13.3mm thick, and it uses Seiko’s proprietary “Super Hard Coating” for scratch resistance. The SPB509 is equipped with a 300m water resistance, an upgrade to 300m water resistance over the previous model, which was rated for 200m. The unidirectional rotating bezel has a ceramic insert with a 60-minute scale that can be used to measure the elapsed time of a dive, and the screw down crown located at 4 o’clock has a deep knurling for ease of use.

The SPB509 has a deep blue dial with an embossed wave pattern inspired by the signature wave mark found on the case back of Seiko diver’s watches since the 1960s. The embossed hour markers are generously lumed with LumiBrite to provide greater visibility in low-light conditions, an essential feature for divers. The gold-tone GMT hand adds a pop of color, creating a contrast against the blue dial.

Seiko Prospex 1968 Heritage Diver’s GMT 60th Anniversary Limited Edition

SPB509 utilizes a 24-hour hand and a fixed 24-hour scale on the dial ring, proving practical and user-friendly for those who need a time display. This means it uses a 24-hour hand and a fixed 24-hour scale on the inner flange. While this is less versatile for frequent time zone changes, it proves to be practical and user-friendly for those who mainly need a dual-time display.

The watch is equipped with caliber 6R54 automatic GMT movement, Seiko’s premier GMT movement for diver’s watches. It has a power reserve of approximately 72 hours, and a GMT function. With magnetic resistance of 4,800 A/m, the movement’s performance remains unaffected by magnetic interference. 

The stainless steel bracelet features a three-fold clasp with a secure lock and push-button release. An important upgrade to this anniversary edition is the slide adjuster, offering a 15mm adjustment range in six increments of 2.5mm. This feature ensures that the watch can be adjusted on-the-go, a requirement for divers wearing wetsuits. On the bracelet, the watch weighs 188 grams, making it substantial on the wrist without being bothersome.

The Seiko Prospex SPB509 60th Anniversary GMT Diver is limited to 6,000 pieces worldwide.

Tech Specs: Seiko Prospex 1968 Heritage Diver’s GMT 60th Anniversary Limited Edition

Reference: SPB509
Movement: Self-winding Caliber 6R54; 72-hour power reserve
Functions: Hours and minutes; central seconds; date; GMT function
Case: 42mm × 13.3mm; stainless steel; rotating bezel with ceramic insert; water-resistant to 300M
Dial: Deep blue with pressed pattern; hour markers and hands with LumiBrite
Strap: Steel bracelet on three-fold clasp with secure lock and slide adjuster
Price: USD 1,750 / €1,900
Availability: Limited to 6,000 pieces