The GMT-Master II is the ultimate luxury watch for frequent fliers, business travellers and globe trotters flying around the world. It evokes intercontinental travel across time zones. Greenwich Mean Time (GMT) marks mean solar time at the Royal Observatory in Greenwich, London – historically the location of the official prime meridian used for calculating longitude and determining different time zones around the world. The GMT-Master was developed to meet the specific needs of airline pilots. It became the official watch of several airlines, including Pan American World Airways, better known worldwide as Pan Am.
In addition to conventional hour, minute and seconds hands, the GMT-Master II features an arrow- tipped hand which circles the dial once every 24 hours, as well as a bidirectional rotatable 24-hour graduated bezel. This 24-hour hand displays the reference time (home time for example), which can be read on the graduations on the bezel.
Travellers can read local time on the dial, indicated by the hour hand. It is easily set, jumping from hour to hour thanks to an ingenious mechanism operated via the winding crown. The adjustment can be made independently of the minute and seconds hands, and without affecting the running of the watch or the reference time. As a result, travellers can simultaneously read the time where they are as well as the time back home.
The bezel was carefully designed to ideally fulfill its function – displaying the time in different time zones. Rolex developed a new bezel rotation system with a spring whose innovative geometry allows the bezel to be turned crisply and securely in either direction and locate with a positive click in each of the 24 hour positions. This exclusive system also ensures reliable functioning of the bezel over time.
The bidirectional rotatable bezel of the GMT-Master II is equipped with a 24-hour graduated Cerachrom insert. The insert, made of an extremely hard and corrosion-resistant ceramic, is virtually scratchproof and its color is unaffected by ultraviolet rays. The numerals and the graduations are engraved in the ceramic and coated with gold or platinum using a PVD (Physical Vapor Deposition) process patented by Rolex. Over and above its functions and its intrinsic technical assets, the GMT- Master II bezel contributes to the model’s strong visual identity.
In 2013, Rolex introduced, as a world first, single-piece, two-color Cerachrom bezel inserts on the GMT-Master II. Blue and black on the 904L steel version of 2013, the Cerachrom insert was launched in red and blue on the 18 ct white gold model presented in 2014. A technical and aesthetic feat, the two-color Cerachrom bezels blend the technical performance of the Cerachrom bezel with the iconic aesthetics of the original GMT-Master.
Like all watches in the Oyster collection, each GMT-Master II is certified as a Superlative Chronometer. This exclusive designation attests that it has successfully undergone a series of tests conducted by Rolex in its own laboratories according to its own criteria, which exceed watchmaking norms and standards. These tests are carried out on the fully assembled watch, in order to guarantee its superlative performance on the wrist.
The precision of every movement – officially certified as a chronometer by COSC (Swiss Official Chronometer Testing Institute) – is, therefore, tested a second time by Rolex after being cased, to ensure that it meets criteria for precision that are far more exacting than those for an official chronometer.
The tolerance for the average rate of a Rolex Superlative Chronometer after casing is of the order of −2/+2 seconds per day. Its precision is tested by Rolex using an exclusive methodology that simulates the conditions in which a watch is actually worn and is much more representative of real-life experience. The certification testing is carried out using state-of-the-art equipment specially developed by Rolex. The entirely automated series of tests also checks the waterproofness, the self-winding capacity and the power reserve of 100 per cent of Rolex watches. These tests systematically complement the qualification testing upstream during development and production that ensures the watches’ reliability, robustness, and resistance to magnetic fields and shocks.
The unique way in which Rolex watches are designed, manufactured and tested, together with the exclusive innovations from which they benefit, push back the limits of performance for mechanical watches and make Rolex the benchmark for watchmaking excellence. The Superlative Chronometer status is symbolized by the green seal that comes with every Rolex watch and is coupled with an international five-year guarantee.
The GMT-Master II’s Oyster case, guaranteed waterproof to a depth of 100 meters (330 feet), is a paragon of robustness. The characteristically shaped middle case is crafted from a solid block of metal: 18 ct gold or particularly corrosion-resistant 904L steel. The fluted case back is hermetically screwed down with a special tool that allows only Rolex watchmakers to access the movement. The winding crown, fitted with the Triplock triple waterproofness system, screws down securely against the case. The crown guard is an integral part of the middle case. The crystal, with a Cyclops lens at 3 o’clock for easy reading of the date, is made of virtually scratchproof sapphire. The waterproof Oyster case provides the GMT-Master II’s high-precision movement with optimal protection.
The GMT-Master II is equipped with caliber 3186, a self-winding mechanical movement entirely developed and manufactured by Rolex. Its architecture, manufacturing and innovative features make it singularly precise and reliable. The oscillator, the true heart of the watch, has a blue Parachrom hairspring patented and manufactured by Rolex in an exclusive alloy. Insensitive to magnetic fields, the Parachrom hairspring offers great stability in the face of temperature variations and remains up to 10 times more precise than a traditional hairspring in case of shocks. It is equipped with a Rolex overcoil, ensuring its regularity in any position. Firmly held in place by a height-adjustable traversing bridge, the oscillator has a large balance wheel with variable inertia regulated extremely precisely via gold Microstella nuts. Caliber 3186 is fitted with a self-winding module featuring a perpetual rotor, which ensures continuous winding of the mainspring by harnessing the movements of the wrist to provide a constant source of energy.