Up until then, multi-time-zone watches were executed in three predominant forms — an additional 12-hour hand, a 24-hour GMT hand, or a Louis Cottier-type world-time system. But the Greubel Forsey GMT provided an unusually poetic interpretation of a highly utilitarian complication, combining a GMT function and a world-timer, along with an actual three-dimensional model of the Earth. Fashioned from titanium, the globe makes one complete rotation every 24 hours anticlockwise — the Earth’s natural rotational direction — in addition to a 12-hour second-time-zone subdial and a cities disk on the back of the watch. The position of the continents on the globe as seen from the north pole can be neatly cross-referenced with the 24-hour equatorial chapter ring that doubles as a day and night indicator.

The World in Focus

In contrast to past GMT models where numerous elements — home time, local time, world time and tourbillon — vie for attention on an asymmetrical dial, the GMT Balancier Convexe adopts a much neater format with both local and world time presented in a concentric configuration, enabling them to be read with greater ease. Home time is read off a small 12-hour subdial, while local time is indicated with a pair of red arrows on a large subdial that spans three-quarters of the watch face. Nestled at the center of it is the beautiful titanium globe that is secured at just one end of its rotational axis — the South Pole — with the continents engraved in relief. It is encircled by a 24-hour chapter ring that has been blackened on one half to distinguish night from day.

All these indications distributed on the front and back of the watch make the Greubel Forsey GMT Balancier Convexe one of the most comprehensive, intuitive and, not to mention, visually spectacular world-time watches on the market. And it doesn’t stop there. At seven o’clock on the dial is the brand’s signature inclined balance wheel. The purpose of mounting the balance at a 30° tilt from the vertical plane is to limit errors in rate caused by gravity in both the horizontal and vertical positions. Additionally, it also adopts traditional approaches to rate stability, such as having a free-sprung balance as well as a hairspring with a Phillips overcoil to ensure better concentricity. The balance has six gold inertial screws that have been inset into its rim to reduce air friction.

Apart from a tiny extension wheel, which drives the small seconds display at five o’clock, the mainspring barrels and gear train are entirely hidden. Like most of Greubel Forsey’s movements, it is equipped with twin fast-rotating barrels to deliver a power reserve of 72 hours. Notably, the second barrel has a slipping bridle, which is a feature usually found in self-winding movements. The slipping bridle holds the outermost coil of the mainspring by friction to the barrel wall. Once the tension gets too high, the bridle slips, relieving excess pressure from overwinding.

The Ultimate Travel Watch

All these fireworks take place within Greubel Forsey’s ergonomic convex case, which marked a new era for the brand when it first debuted in the GMT Sport in 2019.

Superbly constructed, the tonneau-shaped case has a pronounced curvature, enabling it to sit comfortably on the wrist. The oval bezel is curved vertically from 12 to six o’clock such that it appears perfectly round from above. To accommodate the curvature of the case, the crystal is also curved, which further emphasizes the immense depth of the dial. Most notably, the circumference of the bezel extends slightly outward from the case toward the integrated strap, allowing the watch to appear a lot larger than it wears — 46.5mm wide at its bezel with a base diameter of just 43.5mm. Due to the nature of the movement, the case is necessarily thick with a height of 13.75mm excluding the crystal; but with its clever design, which reduces the perceived size of the watch along with its exemplary finishing, it still manages to be rather elegant as far as sports watches go.

The GMT Balancier Convexe is available at Sincere Haute Horlogerie (SHH) boutique at The Shoppes at Marina Bay Sands and at Sincere Fine Watches at Takashimaya S.C., in Singapore.