Seiko Upgrades its Prospex Diver GMT with more WR and a Micro-Adjust Clasp

Surprisingly, Seiko’s first mechanical dive watch with a GMT function was introduced to the collection only two years ago, with the references SPB381, SPB383, and the Save the Ocean limited edition reference SPB385. Inspired by the 1968 Hi-Beat 300m diver, these office GMT watches came with a 200m water-resistance. Only a couple of months ago, during the celebrations for its first dive watch’s 60th anniversary, Seiko released the limited edition SPB509, featuring a wave blue dial, upgraded 300m water-resistance, and a practical micro-adjust clasp. Today, Seiko launches the SPB519 Prospex 1968 Heritage Diver GMT, essentially the same watch in a different colour scheme, but now part of the permanent collection. 

With references SPB381, SPB383, and SPB385, Seiko released its first mechanical GMT dive watch… Indeed, while being active in the field of dive watches for way over half a century, it took a while for the brand to add a traveller’s complication to the mix. There was a lot to love about these watches: they were robust, good-looking (or at least typical of Seiko Prospex), well-made, decently priced, and relatively practical. Some could complain about the office/caller GMT function, some could argue about the water-resistance, and some clearly mentioned the lack of a micro-adjustment system on the bracelet. Some of these issues were solved with the limited edition SPB509, which added more water-resistance and that cool, practical feature on the clasp.

The new Seiko Prospex 1968 Heritage Diver GMT 300m SPB519 is essentially the same watch as March’s limited edition, with a new colour scheme and a streamlined dial. As such, it is a robust, slightly bulky dive watch measuring 42mm in diameter, a decent 13.3mm in thickness and sub-49mm in length. The design is typical late 1960s Seiko, with strong shoulders and a raised unidirectional bezel on top. The latter retains a ceramic insert with a 60-minute scale (so it can be used for diving or timing pasta), which is glossy blue. The case is steel with a super-hard coating, the crown at 4 o’clock screws down and the caseback is solid steel. Compared to the 2023 editions, there’s a bit more thickness, but that’s due to the move from a 200m to a 300m water-resistance.

The dial of this Prospex Diver GMT SPB519 gets rid of the stamped wave pattern of the SPB509, replacing it with a more classic sunray-brushed dial. It’s presented here in a light silvery-white colour, bringing a summery look with the blue bezel. The large markers are stamped and combined with oversized faceted hands; all elements are generously filled with Lumibrite. A red central 24h hand indicates the second time zone, combined with a 24h scale on the inner flange. The date remains at 4:30, and the GMT function is still a caller style.

Inside the case, no changes. We have the in-house, mid-range automatic calibre 6R54 with a 72h power reserve and a 3Hz frequency (accuracy rated in worst cases to +25 to -15 seconds per day). Another important update concerns the bracelet, which retains a classic 3-link construction with brushed surfaces and super-hard coating but, just like the SPB509, adds a six-step on-the-fly micro-adjustment system on the clasp for a 15mm extension range. This is easily done by pressing the two buttons on the side of the clasp.

Available from June 2025, the Seiko Prospex 1968 Heritage Diver GMT 300m SPB519 will be part of the permanent collection and won’t be limited. It is priced at EUR 1,900 or GBP 1,600. For more details, please visit www.seikowatches.com.