The 1960s saw Seiko entering the realm of sports timekeeping for the Summer Olympics in Tokyo, followed by the development of diver's watches and the world's first quartz wristwatch.
In 1965, Seiko premiered Japan's first diver's watch with a water resistance of 150m, as the forerunner of Prospex models designed for adventurers and sports lovers.
Known as the 62MAS, the robust timepiece was ready for adventure and its performance and reliability was proven in the harshest conditions during four missions of the Japanese Antartic Research Expedition conducted from 1966.
This year, the 60th anniversary of the Seiko diver's watch is marked by a trilogy of Prospex models based on the heritage while illustrating the evolution in both functionality and design.
Released in May, the Seiko Prospex 1965 Heritage Diver's Watch pays tribute to the inaugural timepiece.
With a water resistance of 300m, the first 60th Anniversary Limited Edition is housed in a 40mm case made from stainless steel with super-hard coating, and equipped with the automatic Caliber 6R55 delivering a power reserve of 72 hours.
A new dial design is inspired by the wave mark, engraved on the caseback, symbolising the reliability of Prospex diver's watches.
Engraved wave on the caseback symbolises reliability of Prospex diver's watches.
Accordingly, the embossed pattern on the silver-coloured dial captures the rough sea and the force of crashing whitecaps while legibility is enhanced by Lumibrite on hands and indexes.
This mesmerising motif is in blue, changing its appearance according to the viewing angle, on the Seiko Prospex 1968 Heritage Diver's GMT, water resistant to 300m. Without interrupting other hands, the GMT hand can be set independently, and wearer can see at a glance the second time zone.
Launched this month as the second 60th Anniversary Limited Edition, it is powered by the automatic Caliber 6R54 with a frequency of six beats per second while offering a power reserve of 72 hours.
Back in 1968, the precision of the original Professional Diver's 300M was ensured by an automatic hi-beat movement operating at 10 beats per second, enhanced by a manual winding mechanism.
With the characteristic crown at 4 o'clock, the stainless steel case with a diameter of 42mm is matched with a bracelet, which like that of the first commemorative model features an updated clasp.
Allowing a 15mm adjustment range, it can be easily extended or shortened in six 2.5mm increments by pressing side buttons, ensuring a comfortable fit and adapting to changes in wrist size caused by diving pressure or the weather.
Right Limited Edition Seiko Prospex 1968 Heritage Diver's GMT.
These two models for the diamond jubilee of the Seiko diver's watch are available in 6,000 pieces while the third in the trilogy, Seiko Prospex Marinemaster Professional, will be unveiled in July as a limited edition of 600 pieces.
Its exterior echoes the silhouette of the Professional Diver's 300M from 1968 and the construction along with the L-shaped gasket to prevent helium infiltration are inspired by the innovative Professional Diver's 600M from 1975.
The one-piece 45.4mm titanium case ensures water resistance to depths of 600m, suitable for saturation diving, while the motif on the new textured dial evokes the deep sea.
The Marinemaster Professional represents the pinnacle of Seiko's mechanical movements through the new Caliber 8L45 providing a power reserve of 72 hours, with the proprietary alloy Spron designed for durability against breakage, rust and wear ensuring resilience in harsh underwater conditions.
