This is the Greubel Forsey GMT, the latest timepiece from Robert Greubel and Stephen Forsey, masters of watchmaking, masters of innovation. The pair are best known in the industry for their development of the tourbillon, they cannot resist experimenting with its complexities, tweaking it and putting their own "spin" on the fiddley little contraption. Last year Greubel Forsey scooped the Golden Hand award at the 2010 Grand Prix d’Horlogerie de Genève, horological equivalent of the "Oscars" for their superb Double Tourbillon 30° Edition Historique - featuring a tourbillon caged within a cage, inclined at an angle of 30°. The latest release also features a tourbillon - there would be industry rumblings if it didn't, but it is the GMT function which makes this piece special.
Remember the globe that your teacher used to have on her desk when you were a child? Greubel and Forsey bring it to their GMT watch in miniature 3D form to educate, captivate and to indicate the time in locations around the world. The globe constructed from titanium rotates just like the real thing - once per 24 hours, anticlockwise. Around it is a 24 hour ring which serves to reference time with global position - for night-time 6pm to 6am the ring is black, for daytime 6am to 6pm the ring is white.
A cleverly positioned window on the watchcase side works on two levels - it allows in light to emphasise the daytime half of the world and it also enables the wearer to have a continued view of the world.
What this timepiece does is make a complete visual representation of time around the world possible - who is having a sunrise, who is experiencing a sunset, who is awake, who is asleep - instantly. At the 10 o'clock position is a dial for a chosen second time zone with a quick set function on the case side. Also on the 18 carat gold dial are hours and minutes at 1 o'clock, small seconds at 2 and a power reserve indication at 3 o'clock.
The watchcase measures 43.5mm across and is made from white gold, Greubel Forsey do not mind adding the odd bulge on their cases to accommodate their dial indications - they are quite a feature, this one protrudes for both the global sphere and for the tourbillon and still manages to look elegant.
There's more? On the caseback, another superb feature, a disc scripted like an optical illusion, which displays the names of 24 cities around the world. Simply match up a location with its designated local time on either the outer or inner 24 hour ring to set the globe on the dial to the correct position, the inner ring is for cities with summertime. If this sounds confusing, my words are at fault - this is a complex function made simple and user friendly.
Inside and out immaculate hand finishing techniques are showcased. The calibre features two co-axial barrels which give a generous 72 hours of power reserve despite the constant energy required to power the ever-spinning globe and the other indications.
The Greubel Forsey GMT watch comes presented on a hand-sewn black alligator strap.