The SPB519, The Updated Seiko Prospex 1968 Heritage Diver GMT That Does It All

Seiko‘s dive watch legacy is long and rich, yet surprisingly, a mechanical diver with a GMT complication only joined the catalogue in 2023. The SPB381/383and SPB385 laid the groundwork with their “caller GMT x Diver” design, and earlier this year, the SPB509 brought meaningful improvements, including 300m water resistance and a micro-adjustable clasp, wrapped in a limited edition. The latest SPB519 continues that trajectory as it joins the permanent Prospex collection, and while it’s evolutionary rather than revolutionary, it demonstrates that Seiko knows how to listen and iterate.

The SPB519’s case follows the familiar outline of Seiko’s 1968 diver lineage: broad shoulders, cushion-style profile, and functional curves. Crafted in stainless steel with a super-hard coating, with alternating polished and brushed surfaces, the case measures 42mm in diameter, 13.3mm in height, and just under 49mm lug-to-lug. It wears robustly but avoids feeling oversized due to the downward curve of the lugs and relatively balanced proportions. It’s not small, but still manageable for most. Its upgraded 300m water resistance makes it a genuine diver’s companion, unlike the earlier 200m-rated GMTs.

Like many of Seiko’s dive watches, the screw-down crown sits at 4 o’clock, a position that improves comfort and reinforces the professional tool-watch aesthetic. The unidirectional bezel, featuring a glossy blue ceramic insert engraved with a 60-minute diving scale, is finished with a lumed drop within a triangle at zero. It’s tactile, easy to grip, and precise to rotate, as expected from Seiko’s dive bezels. The crystal is a slightly domed sapphire with anti-reflective coating on the inner surface, giving the dial great legibility. The solid screw-down caseback maintains the integrity of the water resistance and features the familiar Prospex markings.

The SPB519 differs most from the limited and blue-toned SPB509 with its streamlined, dressier dial. Gone is the wave-textured motif; in its place, a sunray-brushed silver-white surface that gives the watch a cleaner, fresher appearance. The light dial, paired with the glossy blue bezel, is not only seasonally fitting but also visually balanced, cool, legible, and versatile. It leans slightly more toward a travel and GMT vibe than an outright dive aesthetic.

The raised (embossed) hour markers are oversized, polished, and filled with Seiko’s proprietary Lumibrite, as are the bold and wide sword-style hands. The 24-hour hand, used to indicate a second time zone, is rendered in a contrasting vivid red, giving immediate visibility against the pale dial. Around the periphery, the inner flange carries the 24-hour scale in dark print, keeping the diving capacities on top of the bezel. A rather discreet date window at 4:30 remains, avoiding disruption of the hour markers but continuing to split opinion on symmetry.

The watch remains an office-style GMT, meaning the 24-hour hand is independently adjustable in one-hour jumps, while the main hour hand is linked to the minutes. It’s ideal for tracking home time while travelling occasionally, but not optimised for changing time zones on the fly like a true “traveller GMT.”

The watch is powered by the calibre 6R54, a mid-range automatic movement developed in-house by Seiko. It operates at a 21,600 vibrations/hour frequency and offers a 72-hour power reserve from a single mainspring barrel. It’s equipped with hacking functionality and is regulated to Seiko’s standard -15/+25 seconds per day, though we and many users have seen better real-world performance than this conservative claim.

The Seiko Prospex 1968 Heritage Diver GMT SPB519 has a three-link stainless steel bracelet, which continues the functional aesthetic, finished with a brushed top surface and polished chamfers. Like the case, it’s treated with Seiko’s super-hard coating to resist scratches during daily use. The clasp is the real highlight here, carried over from the limited SPB509. It features a six-step micro-adjustment system offering up to 15mm of on-the-fly extension. No tools are needed; press the two side buttons to slide the clasp and adjust the fit. It’s a genuinely useful upgrade, particularly welcome on hot days or over wetsuits, and addresses one of the previous generation’s biggest criticisms.

The Seiko Prospex SPB519 is a subtle but smart refinement of an already strong platform. It’s still a relatively large watch, and still a caller GMT. But for the occasional globe-trotter, active daily wearer, or anyone who values classic Seiko dive watch character with a bit of extra functionality, the SPB519 is one of the strongest regular-production GMTs the brand has yet released. It is priced at EUR 1,900, now available from retailers and not limited. For more details, please visit seikowatches.com.