Seiko Launch Prospex 60th Anniversary Marinemaster 600m Saturation, 1965 Heritage and 1968 Heritage GMT Divers

I’m willing to admit that it might be hyperbole, but one of the most significant changes in modern horology is Seiko adopting 300m water resistance as the standard for their top end Prospex dive watches. For years it was a constant criticism that their watches had lower resistances than the general standard for professional dive watches despite having the aesthetic down perfectly. Ever since the 1965 Heritage Diver and 1968 Heritage Diver the specs have finally lived up to collectors’ expectations. Just in time for Seiko to celebrate the 60^th anniversary of their first ever dive watch with the launch of a 60^th Anniversary collection that includes new versions of the aforementioned 1965 and 1968, as well as a Prospex Marinemaster ‘Shinkai’ 60^th Anniversary 600m Saturation Diver.

Seiko Prospex 1965 Heritage Diver 60^th Anniversary

If you do the maths, 1965 was 60 years ago, so it’s only right that the 1965 Heritage Diver is the first of the 60^th Anniversary models we look at because it’s a direct tribute to the very first Seiko diver. It has the updated case and 300m water resistance rating of its modern revival collection, measuring 40mm in diameter with a black unidirectional dive bezel. It’s finished nicely as well with brushed lugs and angled facets.

While the case is great thanks to the improved specs of the 2024 revival model, what makes the 2025 edition for the 60^th anniversary special is the dial. It features a motif known as ‘The Great Wave’, a reference to the famous woodblock print by Hokusai. It’s a captivating, geometric pattern with layered waves across the silver display with a strong, stylised visual. The pattern is mildly disrupted by the bar indexes and small, circular date window but thankfully that’s not too severe.

Inside, the Seiko Prospex 1965 Heritage Diver 60^th Anniversary houses the 6R55 automatic movement with 72-hour power reserve, one of Seiko’s higher spec movements. That’s the same movement as the revival models and the price is similar to those watches too at £1,270. It’s also a limited edition of 6,000 pieces, so there is some exclusivity but most people who want one should be able to get one.

Seiko Prospex 1968 Heritage Diver GMT 60^th Anniversary

The Seiko Prospex 1968 Heritage Diver GMT 60^th Anniversary is technically the counterpart of the 1965 as it features the same ‘The Great Wave’ motif on its dial. Though here it’s a dark blue colour rather than silver-white. That’s paired with a blue diving bezel to complete the aquatic ensemble. There are also the added details of this being a GMT model so there’s a 24-hour scale around the peripheral edge of the display – this is actually the first 1968 GMT model to receive the improved 300m water resistance rating.

Structurally the watch has a 42mm diameter case made from steel, which is very standard for a dive watch. Large enough to be easily legible underwater and robust enough to survive a couple of knocks against rocks on the sea floor. Or, you know, scrapes against the office doorknob which is probably the biggest danger most of the people who buy one will face on a regular basis.

Just like the 1965 above, the Seiko Prospex 1968 Heritage Diver GMT 60^th Anniversary is limited to 6,000 pieces, though the price is understandably a higher at £1,600. Due to the increased size and the additional GMT complication present on the 6R54 automatic movement with 72-hour power reserve.

Seiko Prospex Marinemaster ‘Shinkai’ 60^th Anniversary 600m Saturation Diver

If, as a basic rule of thumb, a 300m water resistance rating classifies a watch as a professional diver, then doubling that to 600m makes a watch a saturation diver. Saturation diving involves spending up to 28-days underwater and living in pressurised chambers that mean you don’t have to decompress between dives. Saturation diving is used for underwater construction, maintenance and exploration, all activities that require your watch to be extra robust.

As such, the Seiko Prospex Marinemaster ‘Shinkai’ 60^th Anniversary 600m Saturation Diver has, as its name indicates, a 600m water resistance rating. Resisting that level of pressure for an extended period of time requires incredibly solid construction, which is why saturation divers are larger still even than normal dive watches. The Marinemaster measures 45.4mm in diameter, frankly so that the titanium can be thick enough not to collapse in on itself. Fortunately, the lightweight property of titanium (with super-hard coating for scratch resistance) helps to alleviate some of the weight that would make it difficult to wear.

Aesthetically it has a textured wave pattern dial like the 1965 and 1968 but without the Hokusai stylisation. Instead showing small ripples in the surface of the water on a clear day rather than the stormy Great Wave. The colour is a dark, dark, dark blue inspired by the deep sea, which is what the name Shinkai translates to.

Below the dial is the 8L45, which is even higher spec than the 6R range with an accuracy of +10/-5 seconds per day rather than the +25/-15 of the 6R55 and 6R54 in the 1965 and 1968 editions. It has the same 72-hour power reserve, which is the gold standard of power reserves as it hits the perfect weekend-proof mark, letting you put it down on Friday evening and pick it up on Monday morning without needing to reset it. The 8L45 and the Marinemaster ‘Shinkai’ are both produced in Seiko’s Shizukuishi studio, their highest-end manufacture.

This model is much more exclusive than its 60^th anniversary brethren, limited to 600 pieces at a price of £4,130. Jumping it right to the top of the list as the most expensive Prospex in the existing range, though only by a margin of £30 ahead of the £4,100 1968 ‘Antarctic’ limited edition. As a celebration of Seiko’s 60-year history of dive watches, it’s a fitting tribute.

More details at Seiko Boutique.

​Oracle Time 

Read More