Seiko's green Alpinist GMT goes global as the Prospex HBC007

Seiko just closed one of the more frustrating gaps in its recent catalog. The company has announced the Prospex Alpinist GMT HBC007, an international version of a watch that Japanese collectors have kept to themselves since late 2023. The news surfaced through @plus9time on Instagram, and for anyone outside Japan who wanted the green dial without paying a reseller premium, it is overdue.

What's new

The HBC007 is, functionally, a relabeled SBEJ005, the green-dial GMT Alpinist that launched in Japan on October 7, 2023. Practically nothing has changed in the move to global markets, and that is the point. The dial is the deep green that the Alpinist is best known for, paired with gold-tone hands and applied markers. It is the same combination that made the discontinued SARB017 a cult piece and a long-standing entry point into mechanical Seikos.

The case is stainless steel at 39.5 mm wide, 46.4 mm lug to lug, and 13.6 mm thick. That keeps it firmly in the mid-size territory most buyers actually want, not the oversized dimensions a lot of GMT sport watches drift toward. Seiko ships it on a brown calfskin strap, which suits the field-watch heritage better than a bracelet would.

Inside is the automatic Caliber 6R54. It runs a 72-hour power reserve and adds a GMT hand for tracking a second time zone, with water resistance rated to 200 meters. The sapphire crystal carries anti-reflective coating on the inner surface.

How it compares

The context here matters more than the spec sheet. The Alpinist has carried a GMT complication before, but only as a quartz dual-time model. When Seiko introduced the mechanical GMT Alpinist line in 2023, it was a meaningful step up, giving the family a proper traveler's movement instead of a battery-powered second timezone hand.

The black SPB379 and blue SPB377 both launched internationally at the time. The green SBEJ005 did not. It stayed a Japan domestic exclusive, which is exactly the kind of decision that turns a watch into a gray-market favorite. Buyers abroad either imported it through resellers or went without. The HBC007 ends that, giving the green GMT Alpinist an official global channel for the first time.

The layout is classic Alpinist. The outer bezel uses a 24-hour scale for reading the GMT hand, while the inner rotating ring works as a compass, operated through the crown at 4 o'clock. That compass bezel is a design trait that traces back to the original 1959 Alpinist, so it reads as heritage rather than gimmick.

Who it's for

This is aimed at the buyer who already wanted the green dial and refused to pay import markups to get it. If you own or considered the SPB377 or SPB379, the HBC007 is the variant that was always missing from the international lineup, and it slots in without compromise.

The 6R54 is not chronometer-grade, and the 6R-series accuracy specs are wider than what you get from a Grand Seiko or a Swiss COSC movement. For the segment and the price, though, it is the expected trade-off, and the 72-hour reserve makes it practical to set down over a weekend and pick back up.

Pricing for international markets has not been confirmed. As a reference point, the SBEJ005 carries a Japanese retail price of ¥141,800, roughly $970 at current rates. Expect the global figure to land near that once Seiko publishes regional pricing, which usually follows an announcement like this within a few weeks.