The new Seiko Prospex 1968 Heritage Diver GMT 60th Anniversary SPB509

This year, Seiko celebrates the 60th anniversary of one of its most important timepieces, its first dive watch, the 62MAS. While some would have expected the brand to come with yet another vintage-inspired re-creation of this historic model – it might come later this year – for now, we have a trio of new models. Following the impressive, complex and high-end Titanium Marinemaster SLA081, it’s time for another take on Prospex’s mechanical GMT diver. But there’s more than meets the eye, and it’s not just about the new wave dial. Let’s break down this new Prospex 1968 Heritage Diver GMT SPB509 to see what’s what. 

Seiko’s first mechanical dive watch with a GMT function only appeared in the collection two years ago, with the references SPB381, SPB383 and the Save the Ocean limited edition reference SPB385. As its name suggests, this watch was deeply inspired by the 1968 Hi-Beat 300m diver, sharing the same solid case with strong shoulders, a raised bezel and a crown at 4 o’clock. The watch was equipped with an automatic movement with 72h power reserve, an office GMT function and was rated for 200m water-resistance (important for the rest of the article).

Now, looking at the new Prospex 1968 Heritage Diver GMT 60th Anniversary SPB509, I thought at first that it was just a new dial and a new colour combination. But then, looking at the specs, I noticed that if the diameter (42mm) and the length of the case (48.6mm lug-to-lug) were identical, the new watch was marginally thicker, moving from 12.9mm in the classic models to now 13.3mm. The reason is simple: the watch is now 300m water-resistant instead of 200m water-resistant, and required a more solid caseback and front sapphire crystal.

For the rest, not much has changed, and the difference on the wrist will be minimal, if not imperceptible. The case retains the same shape and design and is made of stainless steel with super-hard coating with brushed and polished surfaces. Despite being a GMT watch, Seiko decided to keep the classic 60-minute diving scale, which is here coated in white on top of a blue ceramic insert. For the rest, no surprises: sapphire crystal with AR coating, screw-down crown and solid steel back.

In addition to this upgraded water-resistance, the Prospex 1968 Heritage Diver GMT SPB509 inaugurates a new dial with an embossed wave pattern – drawing inspiration from the wave mark, a symbol found on the caseback of Prospex diver’s watches. It is here presented in a deep blue colour with crips white-lumed embossed hour markers and hands. The GMT function (an office-like system) can be used thanks to a 24-hour scale printed on the inner flange and an independently set GMT central hand in contrasting gold tone.

Inside the case is the automatic Calibre 6R54, which benefits from a comfortable power reserve like all 6Rxx series movements. It beats at 3Hz and stores up to 72 hours of energy when fully wound. In addition to the time and GMT, it also displays the date. This new model is worn on a steel bracelet with super-hard coating, equipped with a folding clasp and a diver’s extension. That said, this model also benefits from an updated clasp, which allows a 15mm adjustment range, easily extended or shortened in six 2.5mm increments by pressing side buttons.

Available in 6,000 pieces from June 2025, the Seiko Prospex 1968 Heritage Diver GMT 60th Anniversary SPB509 will retail for EUR 1,900. For more details, please visit www.seikowatches.com.