Pan American, commonly referred to as 'Pan Am', was the largest leading international airline during the 20th century, and in the mid-1950s, this pioneer of air travel tasked the pioneer of watchmaking to produce a watch its pilots could rely on for tracking multiple timezones at once during long-haul flights. Rolex achieved this by adding a fourth hand that journeyed around the dial once every 24 hours. This, combined with a 24-hour scale bi-directional rotating bezel with a split colour configuration to indicate daylight and nighttime hours at a glance, was the birth of the GMT-Master. Since then, the GMT-Master has experienced many iterations, simultaneously gaining in popularity as one of the leading sports models for the Coronet and as the pinnacle of globe-trotting watches. 

Reference 1675: Gilt to Matte, The Longest Running Reference (1959-1980) 

Compared to the very first iteration of the model, the reference 6542, the 1675 transitioned to using an aluminium bezel over the more fragile bakelite, and the case size increased from 38mm to 40mm, a size the watch has remained ever since. Debuting in 1959, the Ref. 1675 was in the collection for 21 years, and during the two decades, it underwent many quality-of-life evolutions. Until approximately 1967, the 1675 had glossy black dials, with gold-toned text and markers produced through a layering technique that reveals the lettering beneath the lacquer. Known as 'gilt', these dials were later replaced by matte dials in the late 1960s and remained the standard until 1980. The Rolex 1565 calibre powers early examples of 1675, however later models from approximately 1971 saw a calibre change to 1575, which has an increase in beat rate, along with the ability to stop the second's hand once the crown is unscrewed and pulled out.

This example comes from 1973, making it a matte dial, calibre 1574 powered piece with tritium lume.

Reference 16700: The Dawn Of Super-LumiNova and Sapphire Crystals (1988-1999)

The 16700 ran from 1988 until 1999, with its nuances reflecting the modernisation of the watch industry during these two decades. This reference was the last model within the 'GMT-Master' collection, a change which goes past just a name change as the Master II arrived in a reference that pre-dates this, the 16750. Nevertheless, the 16700 GMT-Master remained and is powered by the calibre 3175, a movement with a quick set date function. The watch features a scratch-resistant sapphire crystal, and just like the 1675, minor changes occurred within this series over its 11-year lifespan, with a transition from tritium to the modern, brighter, longer-lasting Super-LumiNova in 1997. The dial is also glossy and includes 18ct white gold surrounds for its markers. 

Reference 16710: An Independently Set GMT Hand, The Calibre 3185 (1989-2007)

The 16710 is another longstanding GMT reference, lasting 18 years between 1989 and 2007. Within this period, the watch industry transformed from steel sports watches being viewed more as luxury items than tools. As such, the 16710 is a modern reference where various bezel iterations were available from the classic red and blue, known as Pepsi by collectors, black and red or 'Coke', and an all-black. The 16710 is the second generation of the GMT-Master II and is powered by the calibre 3185, an updated movement that introduced the ability to independently set the local hour hand in one-hour increments, while the GMT hand and minute hand continue to run uninterrupted. This practical feature allows for quick time zone adjustments without stopping the watch, as most zones shift by whole hours.

This example, produced in 1999, features the black and red bezel insert known colloquially as the ‘Coke’. 

Reference 116710: A Modernised Case, Ceramic Bezel, and Advanced Calibre (2007-2019) 

In 2007, Rolex revealed a refreshed expression of the GMT Master II with extensive advancements inside and out. Visually, two significant changes arrived in the form of a new, bolder, and more striking case presence called the 'Super Case', which is colloquially known as the 'maxi case'. This change saw the wrist presence of the Rolex sports watch leap forward to a very modern, bold look; nevertheless, it retains its 40mm width. The 24-hour bezel has also been upgraded to a scratch- and ultraviolet-resistant ceramic called Cerachrom. Mechanically, the 116710 is powered by the Calibre 3186 featuring a Parachrom hairspring, which is anti-magnetic, less impacted by variations in temperature, and has more shock resistance over previous movements, as such increasing the long-term reliability and accuracy. Other more subtle changes of the 116710 are the thickness and increased size of the hour markers and handset. 

This example, introduced in 2013, is a piece which features a blue and black bezel configuration, colloquially referred to as the 'Batman'.  

Reference 126710: A Future Proof GMT-Master II (2018-Present)

The latest and current iteration of the GMT-Master II first debuted in 2018 under the reference 126710, and with it reunited stainless steel and the 'Pepsi' bezel after it had spent four years only available within the white gold iteration of the watch, the reference 116719. Furthermore, the 126710 was the first time the 'maxi' case era of GMT-Master II was produced on a jubilee bracelet. This reference includes major upgrades, such as a new calibre, the 3285, which significantly advances efficiency, durability, and accuracy. Firstly, the power reserve is increased from 48 hours to 70 hours, the Chronergy escapement is used, the gearing is optimised for efficiency, a new barrel architecture, and there are further advancements with shock and magnetism resistance. To contextualise the importance of this calibre, Rolex applied for ten patents just for this movement. Fitted on its jubilee bracelet with its Oysterlock clasp and 5mm of quick adjustments, this is an exemplary example of one of the most popular Rolex sports watches today.

Reference 126720VTNR: A Left Field Evolution (2022-Present)

In 2022, the reference 126720VTNR marked a significant shift in the GMT-Master II lineage as Rolex unveiled its first left-handed crown placement within the modern collection. This subtle reversal sees the crown and crown guards placed on the left side, and it was a move few expected. This change favours left-handed people, as the crown and guards do not dig into the arm by wearing this GMT on the right hand. Alongside this, the date window was repositioned to nine o'clock, requiring a re-engineered movement architecture within the Calibre 3285 to accommodate the flipped layout. The VTNR, short for "Vert Noir" (Green Black), has a bezel split between green and black Cerachrom, a first combination for the GMT line. This variation continues using the robust 3285-LHD movement with its Chronergy escapement and 70-hour power reserve, maintaining the technical edge introduced with the 126710. Fitted on an Oyster or Jubilee bracelet and retaining the modern maxi case and anti-reflective sapphire, this particular example is seen on the Jubilee. 

 

The GMT-Master has perfected the balance between change and familiarity. Over the years, its case has evolved, new materials have been used, and calibres have improved, yet the core idea of a watch built for crossing time zones hasn't wavered. It remains unmistakably worn by pilots and those drawn to its quiet conviction. The charm isn't in what it says but in how little it needs to.