From 200m to 300m, a quiet path to the definitive version of a Prospex GMT diver
Some watches are known by their nicknames before their names. The Seiko Prospex 1968 Heritage Diver’s GMT HBC001 is one of them. The official name is long and complicated, so people just call it two things. Hulk, because it’s green. And the Ohtani watch, because Ohtani wears it.
Neither name came from Seiko. But those nicknames summarize the watch’s identity precisely.
The Hulk Nickname
Hulk originally belonged to the all-green version of the Rolex Submariner. Green dial, green bezel. Watch enthusiasts call this green-on-green combination the Hulk. Seiko has several such green divers, and the HBC001 is the newest among them. A deep green dial paired with a matching green ceramic bezel, contrasted by a gold-colored GMT hand. The black version is sold separately as the HBC002.
The dark green is especially good in person. Not a bright green but a deep, restrained shade that shifts tone with the light. The contrast with the gold GMT hand defines the watch’s character.
Why It’s Called the Ohtani Watch
The 1968 Heritage GMT line that HBC001 belongs to is the series Shohei Ohtani has worn as a Seiko Prospex ambassador. There are separate Ohtani-specific limited editions (SBDC191, and the 2026 SBDC222), but this standard GMT line also came to be known as the Ohtani watch after he wore it. To be precise, it isn’t a limited edition made for Ohtani. It’s a standard model he happens to favor. That distinction is worth knowing.
The best baseball player in the world choosing a watch in the four-figure range over one costing tens of thousands. That fact alone became this watch’s most powerful marketing.
A Quiet Upgrade
The real story of the HBC001 isn’t design. It’s refinement. This is the standard model replacing the SPB383 (green) released in 2023. The exterior is nearly identical. You’d have to stare at the two side by side for a full thirty seconds to notice that the water resistance marking on the dial changed from 200m to 300m.
But important things changed inside.
Water resistance was strengthened from 200m to 300m, a 50% improvement. And yet the case thickness stayed almost the same. Increasing water resistance usually means adding thickness, but Seiko resolved that physical tradeoff. A new six-step micro-adjust clasp was also added. On top of a diving suit or on a wrist swollen in summer heat, you can fine-tune the bracelet length on the fly. It’s a feature that debuted on the flagship Marinemaster and has now trickled down to this line.
The movement is Caliber 6R54, part of Seiko’s first mechanical GMT diver movement family. Automatic, 24 jewels, 21,600vph, roughly 72 hours of power reserve. It uses the traveler GMT system that adjusts the GMT hand independently in one-hour increments, so you can read a second time zone without stopping the watch.
Specs and Price
The case is 42mm in diameter, around 12.9mm thick, 48.6mm lug-to-lug. An angular case reinterpreting Seiko’s 1968 professional diver, with mirror-polished sides and a screw-down crown at 4 o’clock. Sapphire crystal, Lumibrite indices and hands.
Price runs between $1,500 and $1,700 in the US and around €1,900 in Europe, listed slightly differently across outlets. It varies by region and channel, so confirm before buying. The official Korean price is best checked through Samjung Watch. Release is spring 2026. It’s a standard collection model, not a limited edition, so you can buy it if you want it.
Case thickness is listed as both 12.9mm and 13.3mm depending on the outlet, and warrants confirmation.
Editor’s Note
While H. Moser sold playfulness with a basketball-shoe button on a forty-thousand-dollar watch, and Omega brought a video game’s Bond watch into reality, Seiko was doing something else. Taking a good watch from three years ago and quietly making it better, with no loud announcement.
The HBC001 is not a new watch. It’s the definitive version of one that was already good. Raise the water resistance, improve the clasp, and leave the rest untouched. The attitude of not changing what has no reason to change. That’s what makes this four-figure diver trustworthy.
The reason the best baseball player in the world wears it probably lies there too. A watch speaks through attitude more than numbers. The green of the HBC001 is the color of that attitude.
Seiko Prospex 1968 Heritage Diver’s GMT HBC001 (HBC001J1) | Released spring 2026
Price: US $1,500–$1,700 · EUR €1,900 (Korean price to be confirmed)
Case: 42mm diameter · approx. 12.9mm thick · 48.6mm lug-to-lug · stainless steel
Water resistance: 300m (up from 200m on the SPB383) · green ceramic unidirectional bezel
Dial: deep green · gold GMT hand · Lumibrite
Movement: Caliber 6R54 · automatic GMT · 24 jewels · 21,600vph · approx. 72h power reserve
Features: six-step micro-adjust clasp · traveler GMT · sapphire crystal
Nicknames: Hulk (green combo), Ohtani watch (standard line he wears) · black version HBC002
Predecessor: SPB383 (2023, 200m)
