The Greubel Forsey GMT is one of the most fascinating worldtimer complications we have ever reviewed. This fascinating watch created by Robert Greubel and Stephen Forsey, founders of Greubel Forsey will leave you in awe. Last week, we were able to peruse the watch and meet with Stephen Forsey who explained in detail how this fascinating complication works. 

Robert Greubel —a former IWC employee that worked on their Grand Complication Project and prototypist for complications at Renaud & Papi— and Stephen Forsey have been working together for nearly 20 years. In 1992, Stephen met Robert at Renaud & Papi and in 2001 they co-founded 'Complitime', a company focused on developing and crafting complicated movements for prestigious brands.

In 2004, Robert and Stephen unveiled 'Greubel Forsey' and stunned watch collectors with their innovative Double Tourbillon 30°. The GMT we are reviewing here is no exception as Greubel Forsey continues to take horology to the next level.

This GMT complication, available in rose gold or white gold, features a second time zone indication complemented by a three-dimensional terrestrial globe providing an intuitive picture of time all over the world in a distinctive asymmetrical case measuring  43.5 mm in diameter and 16.14 mm in thickness. A dual-function pusher located on the left caseband —at what would be the 10 o'clock position— with GMT engraved on it, allows for quick setting of the second time zone that is indicated on a small register at 10 o'clock as well as adjustment of the rotating globe that is synchronized with a cities disc on the back of the watch. The dial features a 72-hour power reserve indicator at 2 o'clock right underneath the seconds register. The local time is shown on the off-centered gold frosted anthracite treated dial at 12 o'clock. The sapphire crystal opening on the caseband at 7 o'clock allows for full view of the delicately finished terrestrial globe and to allow for light to go in which indicates those areas of the world where it is daytime. The terrestrial globe makes one complete rotation every 24 hours anticlockwise —the Earth’s natural rotational direction viewed from North pole— and the position of the continents can be easily cross-referenced with the time on the equatorial chapter ring which is marked with 24 time zones and day/night indication. The night-time hemisphere —18:00 to 6:00— is indicated by a blackened half of the ring around the globe, while the daytime hemisphere —6:00 to 18:00— is indicated by a whitened portion. Midnight is indicated in red while noon is in yellow.

The 25° inclined Tourbillon '24 Secondes' cage at 5 o'clock is one of Greubel Forsey’s major patented inventions. The single inclined tourbillon cage undergoes rapidly changing positions with a high angular velocity, thus minimizing the effects of gravity on the regulating organ and maximizing timekeeping accuracy. 

Now, let's talk about the back of the watch. As fascinating as the front, the back features a worldtimer disc with 24 cities that eases the setting of the globe and also provides the traditional worldtimer way of reading time in multiple timezones. As the cities disc rotates, so does the terrestrial globe to perfectly show night and day areas of the earth. The disc is also fitted with a central indicator for Summer Time a.k.a. Daylight Savings Time. Those cities not using DST are on a dark background and time is read on the outer chapter ring. It is worth mentioning that the anti-reflective coating treatment on the sapphire crystal of the display case back makes the cities disc appear grayish; however, the disc is made of sapphire crystal and the cities are in black and white as the last picture clearly shows it.

The back also features a golden gear with a beautiful windrose serving as a useful visual reference for midday. The beating heart inside this watch is the manual wound calibre GF05 decorated with nickel silver frosted bridges and plates, blued screws and a small opening where the efficient spherical differential can be admired. This calibre is composed of 443 parts, 50 jewels and two co-axial series-coupled fast rotating barrels. 

The caseband is matte finished with alternating polished areas around the lugs and with polished edges on the bezel and the case back. A nice contrasting touch to the beautifully engraved black lacquered winding crown.  

This fascinating piece of horology is fitted with a beautiful and very comfortable blue crocodile strap with deployant buckle. The strap is extremely elegant and nicely handcrafted.

Opposed to the thick construction of this watch, it does not sit high on the wrist and is extremely comfortable wearing true to its diameter. If you are ready to own one of the masterpieces of modern horology, look no further. This is a real GMT watch that very few will be able to own. Please enjoy the video at the bottom of the post where Robert and Stephen clearly explain how this fascinating timepiece works. 

Sticker Price $595,000 USD. For more info on Greubel Forsey click here.