The GMT function has long enjoyed a place in Grand Seiko’s catalog, offered across every collection and movement range – from Hi-Beat and standard mechanical to Spring Drive and quartz. Last year, Grand Seiko unveiled several notable GMT models, among them the popular Spring Drive ceramic GMTs, which included the limited SBGE263 “Eagle.” But before those came to light, over the summer of 2020 Grand Seiko also quietly released two other Hi-Beat GMTs in the Sport Collection: SBGJ237 and SBGJ239. Today, we’ll take a closer look at the SBGJ239.
SBGJ239 has a “Vintage Green” sun-ray dial. 
Grand Seiko SBGJ239 Hi-Beat GMT green-dial men’s wristwatch
The stainless steel case measures 44.3mm in diameter, 14.4mm in thickness, 51mm in length, 21mm in lug width, and it’s rated to 200 meters. The case has a nice sense of balance, resulting in a watch that feels just right on the wrist. Despite its larger diameter, the case wears and looks smaller than its given dimensions. There are several reasons for this. First, the lugs curve down gently, tempering their presence. Second, the crown moved from the traditional three o’clock position and offset to four o’clock makes the case look smaller along its horizontal axis. And third, the bezel takes up some of the real estate on the dial-side of the watch, which means that the dial doesn’t feel overly large. Altogether, this is a thoughtfully proportioned design.
The bezel is bi-directional and features a 24-hour scale. The action of the bezel is excellent in hand, and the grooves along the edge allow for an easy and secure grip. The bezel features a sapphire overlay, making it extremely durable. Synthetic sapphire is the hardest of all known oxide crystals, coming in at 2,500-3,000HV, so it is highly resistant against scratches. The sapphire overlay also protects the luminous material underneath. And speaking of luminous material, SBGJ239 glows like a torch in the dark thanks to Lumibrite, with all the white portions on the bezel glowing a bright green (matching the luminous paint on the dial). One interesting detail to note is that the black-colored portion of the bezel (from “18” to “6”) extends further out than the white portion of the bezel. This was done so as not to bisect the “18” and “6.”
The dial is “Vintage Green” with a sun-ray pattern. Depending on how the light hits the dial, the green can look darker or lighter. The indexes are bold, sculptural, and beautifully finished. As is the case with all Grand Seiko indexes, these make full use of the interplay of light and shadow, giving them a striking appearance every time you look down at the watch. They feature ample Lumibrite paint at the cardinal points, lending to excellent nighttime visibility. The top surface of the hour and minute hands feature hairline finishing, which keeps them from getting lost against the darker colored dial. Accenting the green is a splash of red found on the “GMT’ text on the dial and on the GMT arrow hand, also finished with luminous paint.
Running at 36,000 bph, Caliber 9S86 has a 55-hour power reserve and an accuracy rating of +5/-3 seconds a day. It also gives SBGJ239 true GMT functionality.
This means that the local hour hand is independently adjustable while the GMT hand remains fixed to the “home” time (which is whatever non-local time you’d like to track). The benefit of this sort of functionality is that upon arriving to a new locale in a different time zone, the wearer can quickly jump the hour hand to the appropriate hour without having to reset the watch. For example, if one were traveling across the country from California to New York, they would simply jump the hour hand forward three positions upon arrival to account for the three-hour time difference. The GMT hand would remain unchanged, continuing to track the second time zone. It should also be noted that because there are two 24-hour tracks on the watch – one on the chapter ring of the dial and one on the bi-directional rotating bezel – SBGJ239 can be used to track a total of three time zones.
Strap changes are made easy courtesy of the drilled lugs, and though SBGJ239 comes mounted on an elegant crocodile strap this is an easy watch to dress up or down with a simple swap of the strap.
Overall, with its robust sporty build, high-performance movement, and striking appearance, SBGJ239 makes for a reliable and exciting travel companion that can adapt to any situation.
Case: Stainless Steel
Dimensions: 44.3mm in diameter x 14.4mm in thickness x 51mm in length
Movement: 9S86 Hi-Beat 36000 GMT Automatic
Availability: Grand Seiko Boutiques, Salons, and the GS9 Club Shop
