Seiko’s modern 1968-inspired diver GMT has always made sense on paper, but the latest black and green versions feel like the most rounded executions yet.
The new Prospex 1968 Heritage Diver’s GMT HBC001 and HBC002 keep the established case, bezel and Calibre 6R54 architecture, then add two upgrades that matter in daily use. Water resistance now rises to 300 metres, while the bracelet gains a more useful six-step micro-adjustment system.
At a glance
- Seiko has added two non-limited Prospex 1968 Heritage Diver’s GMT models in black and green.
- Both watches feature 300m water resistance, ceramic dive bezels, LumiBrite detailing and the automatic Calibre 6R54 GMT movement.
- The HBC001 and HBC002 are part of the permanent collection and are priced at EUR 1,900.
A stronger permanent-collection dive GMT
The HBC001 and HBC002 arrive as successors to the first mechanical Prospex diver models with a GMT function, the SPB381 and SPB383 introduced in 2023.
Rather than chasing a themed dial or limited-edition identity, these two watches lean into the core brief of the collection. They’re practical, legible, and familiar in the way a good Seiko professional-style diver should be.
The most important change is the move from 200 metres to 300 metres of water resistance.
That detail pushes the watch closer to Seiko’s more tool-focused dive-watch territory, and it gives the GMT format a more convincing purpose beyond travel and office wear.
The 1968 case profile stays intact
The stainless steel case remains 42mm across, 13.3mm thick and 48.6mm lug-to-lug, dimensions that have become central to this Prospex family.
Its shape draws from Seiko’s 1968 professional diver, with crisp case lines, brushed and polished finishing, mirror-polished sides and a screw-down crown at 4 o’clock.
The unidirectional bezel uses a ceramic insert with a 60-minute diving scale, while the deeply knurled edge is designed for secure handling.
Seiko offers two straightforward colourways here. The HBC001 uses a black dial and black bezel, while the HBC002 pairs a green dial with a matching green bezel.
Both dials use large applied indices, broad hands and generous LumiBrite on the hands, markers and bezel for strong low-light readability.
The bronze-toned GMT hand tracks a 24-hour scale on the inner flange, while the date sits discreetly at 4:30.
A red-and-white tipped central seconds hand gives the watch a small visual lift without softening its otherwise functional character.
Calibre 6R54 and the clasp upgrade
Inside both references is Seiko’s automatic Calibre 6R54, an in-house movement with manual winding, hacking seconds and a 72-hour power reserve.
The GMT function is the caller-style arrangement, meaning the 24-hour hand is independently adjustable to display a second time zone.
That setup is especially useful for tracking another market, home time during shorter trips, or colleagues in another region, even if it isn’t the flyer-style GMT layout preferred by some frequent travellers.
The bracelet update may be just as meaningful as the improved depth rating.
Seiko has fitted a redesigned three-fold clasp with push-button release, secure lock, diving extension and a six-step slide-adjustment mechanism offering approximately 15mm of tool-free extension.
For a watch meant to move between desk, travel and water, that kind of on-the-fly sizing makes a real difference.
Details & Specifications
| Brand | Seiko |
|---|---|
| Collection | Prospex 1968 Heritage Diver’s GMT |
| References | HBC001 black, HBC002 green |
| Case size | 42mm diameter, 13.3mm thickness, 48.6mm lug-to-lug |
| Case material | Stainless steel with brushed and polished surfaces |
| Bezel | Unidirectional bezel with black or green ceramic insert and 60-minute scale |
| Crystal | Sapphire crystal with inner anti-reflective coating |
| Crown | Screw-down crown at 4 o’clock |
| Water resistance | 300 metres |
| Dial | Black for HBC001, green for HBC002, with LumiBrite markers and hands |
| Movement | Seiko Calibre 6R54 automatic |
| Jewels | 24 |
| Frequency | 21,600 vibrations per hour |
| Power reserve | 72 hours |
| Functions | Hours, minutes, seconds, independently adjustable 24-hour GMT hand and date |
| Bracelet | Stainless steel bracelet with 20mm lug width |
| Clasp | Three-fold clasp with push button, secure lock, diving extension and six-step micro-adjustment |
| Availability | Permanent collection, now available |
| Price | EUR 1,900 |
The HBC001 and HBC002 don’t reinvent Seiko’s 1968 Heritage Diver’s GMT, and that’s part of their appeal.
They refine the formula in the places owners are likely to notice, making these black and green references the cleanest everyday versions of the model so far.
