Understanding The Rolex GMT-Master

July 15, 2020

Understanding The Rolex GMT-Master


Rolex is known for designing and creating watches specifically for special populations of sportsmen and adventurers. One example of this type of timepiece is the Rolex GMT-Master wristwatch. As the flight industry started to really take off during the 1940s and 1950s, pilots began flying longer distances. Originally designed in collaboration with Pan Am Airways, the Rolex GMT-Master was initially created for Pan AM, and issued by them to their crews on long-haul flights. The key feature of the watch was that it allowed the wearer to simultaneously reference two different time zones. The original GMT-Master watch has a fourth hand (24-hour display) that displays the same time zone as the standard 12 hour hand. The GMT hand enables the wearer to set the watch to Coordinated Universal Time (UTC) or any other time zone for the main time view, then set the rotatable 24-hour scale bezel to a second time zone. The GMT name is derived from Greenwich Mean Time. Greenwich Mean Time is also known as Coordinated Universal Time, and is the time zone that is required for all aviation planning, weather forecasts, and schedules.


The first GMT-Master model was the ref. 6542 (gold version pictured below), which was essentially a regular Rolex Turn-O-Graph ref. 6202 with a different bezel and additional 24-hour hand. It was produced from 1954-1959, and was pressure proof up to 50 meters (165 feet). The first version of the ref. 6542 had a luminous bakelite bezel insert. However, this bezel soon proved unacceptable, as it easily cracked. Consequently, a new metal bezel was introduced in 1956. The first GMT-Master is also fondly nicknamed the “Pussy Galore,” as it was famously worn by "Pussy Galore" (actress Honor Blackman) in the 1964 James Bond film, Goldfinger.


The GMT-Master ref. 1675 was introduced in 1959, and was produced until 1980. It featured the caliber 1565 until 1964, when it was replaced by the caliber 1575; hacking was introduced in 1971. Like the original GMT-Master, the ref. 1675 promised a water resistance rating of 50 meters (165 feet). However, unlike the original model, the ref. 1675 featured crown guards and new dial inscription reading “Superlative Chronometer Officially Certified." The ref. 1675 also came in several variations, including a gold version with a leather, Oyster, or Jubilee bracelet, along with a steel and gold version that also featured an Oyster or Jubilee bracelet.


A new version, the ref. 16750, was introduced in 1981 and was produced until about 1988. The ref. 16750 features the caliber 3075 movement, which offers hacking and a quickset date. Unlike its predecessor, the ref. 16750 increased its water resistance rating, ensuring pressure resistance up to 100 meters (330 feet). The new model also offered two different dial variations, including one with a matte finish with printed luminous indexes, which is considered very rare, and a glossy version, featuring applied white gold indexes. During routine service, many matte dials were replaced by glossy dials, which has led to their rarity.

In 1983, the Rolex GMT-Master II ref. 16760 (pictured below) was released. Despite this new model, production of the original GMT-Master (with modifications) continued until the late 1990s. On the outside, the two versions of the GMT-Master look nearly identical. However, their biggest differences lie within. The GMT-Master II utilizes a movement that has the additional capability of an independently adjustable hour hand, which can be adjusted in one-hour increments without stopping the second hand or disturbing the minute hand or 24-hour hand. This version of the GMT-Master II also features a rotatable bezel, allowing the wearer to easily reference a third time zone. The original GMT-Master II is fondly nicknamed the “Fat Lady” as its case is thicker than the original GMT-Master. Despite its larger case, the GMT-Master II is very aesthetically appealing. It is the first GMT to feature white gold indices borders and a sapphire crystal. Only produced in steel, it did offer any bezel color options, and was instead only available with a new red and black color combination.

Despite the release of the GMT-Master II, production of new models of the original GMT-Master continued. From 1988 to 1999, the GMT-Master ref. 16700 was produced, with the ref. 16700 replacing the ref. 16750. Powered by the caliber 3175, the ref. 16700 GMT-Master maintained the non-independent hour hand, and only allowed users to simultaneously reference two time zones, while owners of GMT-Master II watches like the ref. 16760 and ref. 16710 had the ability to reference a third. 

THE GMT-MASTER II 116710 & 126710

In 2005, Rolex updated the GMT-Master II. The new design was initially exclusive to the all-gold version of the watch (ref. 116718); however the new model featured a number of technical changes. Utilizing technology from other designs, Rolex added a larger Triplock winding crown, which was originally featured on their divers’ watches. Rolex also utilized their patented Parachrom hairspring. Aesthetically, the new model changed significantly. Featuring a larger case and larger hands and hour markers gave the GMT-Master II a fresh, new appearance. A new bezel, made from an extremely hard and proprietary ceramic material was also added, which was designed to be virtually scratch and fade-proof. The style of bracelet also changed dramatically, incorporating solid center links and a completely redesigned clasp.

In 2007, Rolex introduced the GMT-Master II ref. 116710, which brought the new design that was first unveiled in 2005 to the stainless steel version of the GMT-Master II. Like its predecessor, the ref. 116710 is water resistant to 100 meters (330 feet). Additionally, like the ref. 116718, the new model introduced several new features, including an anti-reflective Cyclops lens, green 24-hour hand, maxi dial, ceramic bezel with 24 clicks rather than 120 clicks, and a completely re-designed bracelet. Inside, the ref. 116170 features the caliber 3186 movement, which offers minor improvements including a new Parachrom Bleu hairspring, which was developed after years of research and helps to improve both timekeeping and reliability. Crafted from a highly stable paramagnetic alloy that includes niobium and zirconium, it is insensitive to magnetic fields and up to 10 times more resistant to shocks than traditional hairsprings.

Rolex released their latest GMT at Baselworld in 2018 - the GMT-Master II reference 126710 BLRO. Although Rolex had recently released a white gold version of their classic GMT-Master "Pepsi" bezel, they doubled down on their most famous color combination and constructed their new GMT from their patented Oystersteel, and placed the watch on a stylish Jubilee bracelet. Internally, the ref. 126710 BLRO also saw an upgrade, and features the caliber 3285, which uses Rolex's patented Chronergy escapement and allows the watch to have an extended three-day power reserve. 

At Baselworld 2019, just one year after the introduction of the stainless steel "Pepsi" GMT-Master II ref. 126710 BLRO, Rolex discontinued the ref. 116710 GMT-Master II completely. Both the version with the all-black bezel insert and green 24-hour hand, and the black and blue "Batman" GMT-Master II were discontinued, and in their place, Rolex introduced the ref. 126710 BLNR GMT-Master II. Mechanically identical to the "Pepsi" GMT-Master II that was released a year before, the new ref. 126710 BLNR "Batman" GMT is very much the same watch, but with a blue 24-hour hand and a black/blue "Batman" bezel insert. The release of the ref. 126710 BLNR "Batman" GMT-Master II marked the end of Oyster bracelets and all-black bezel inserts being options on stainless steel GMT-Master watches. Currently, stainless steel Rolex GMT-Master II watches are only sold with bi-color bezels and on Jubilee bracelets. 

Although the GMT-Master was initially designed for use by professional pilots as a tool, its combination of functionality and aesthetic appeal has attracted a much wider audience. Suitable for globetrotting, or simply as an everyday watch, the GMT-Master’s versatility makes it a perfect single purchase or an excellent addition to any Rolex collection.

Source: https://www.bobswatches.com/watch-resources/rolex-gmt-master-history