Rolex History
Rolex Company
Model References
Clasp Codes
Code on Certificate
Authenticity Elem.
Luminous Material
Fitting of the new flat links bracelet
Compass Trick
Tachymeter – How to
Watch fairs
Fitting a bracelet
Mount Natostrap
Cleaning a watch
Polishing a bracelet
Polishing a housing
Remove Scratches
GMT-Master – The History
The history of the Rolex GMT Master is a very special one. The idea for the watch came not from Rolex itself, but from Pan American Airlines (Pan Am). Due to its transatlantic flights, Pan American Airlines needed to give its pilots a timepiece that could display two different time zones at the same time.
The early GMT-Master – 6542
Pan American Airlines took the idea to Rolex and Rolex delivered a new Rolex in 1954, the "GMT Master" with reference number 6542, which was designed specifically for this purpose. The watch was a great success; It was introduced by Pan Am as its official timepiece. Many other airlines followed.
The very first models of the GMT with reference number 6542 did not yet have the typical "GMT-Master" on the dial, but – and therefore they are very easy to recognize – ("50m = 165ft") was imprinted in red at the 6 o'clock position on the dial.
Another special feature of the early GMTs is the bezel. This was not made of ceramic or metal as it is today, but from Bakelite. Bakelite was the first fully synthetic, industrially produced plastic. This was resistant to mechanical effects (pressure), heat and acids, but also rather brittle, which made it susceptible to tensile stresses. Often a lateral force from an impact to the door frame or door handle or even an impact on the ground, was sufficient to make the bezel break out of the material. This is the reason why most of the bezels were already been broken after only a few years. Watches with original, unbroken bakelite bezels are extremely rare and makes them very coveted for collectors. The bezel of a Rolex GMT Master 6542 now makes up a very large part of the value of the watch.
There are different versions of bakelite bezels. The very first series of 6542 models had a bakelite bezel with an extremely high luminosity. They can be recognized by the division of the red/blue scale – the blue of these bezels ends right before the "6" and the "18," while the scaling of the second series is between the two numbers.
Rolex 6542
Picture: ©Rolex/Jean-Daniel Meyer
Myth white GMT
As with many other watches, there is also a myth about the GMT, which certainly falls into the "yarn" category – the special version with a white dial:
GMT with white dial, probably not authentic
Picture: www.fiftyfathoms.net
The reason for this special variant was as follows: After the pilots were equipped with the new timepieces, the ground crew asked for the same watches as the pilots. That is why Pan Am ordered a very small number of modified GMTs with a white dial (supposedly less than 200 copies) from Rolex. The watches for the ground crew needed to be distinguished from the watches for the flight crew. Black dials were therefore provided for the flight crew, while the watches with the white dials were for the ground crew.
White GMT models are often found even at well-known auction houses and surprisingly often achieve top prices at auctions, but their authenticity and existence cannot be confirmed anywhere else.
Back to the "normal" GMTs:
GMT-Master 1675
As early as 1959, Rolex introduced the successor of the GMT Master with reference number 1675, which by 1980 was produced for more than 20 years. Therefore, this model is probably the most famous reference number and still very popular today. It's not so easy to get a good GMT, now, and the prices are extremely high. All the good models have already been landed by collectors and they are not so easy to get.
During the long production period, however, there were some model revisions:
As with the first models of the Rolex Submariner, the first GMT Master models had no protection for the raised crown. This feature was added to the GMT only in the early 60s, starting from reference number 1675. The first models had the so-called "pointed crown guards ," a pointed crown protector. A more rounded version came out in the late 60s.
With reference number 1675, the dial code lettering also changed: the phrase "Official Certified Chronometer" on the dial differed from the "Superlative Chronometer Officially Certified" text.
In the early 1960s, Rolex changed the color of the lettering on the dial from gold to white. At the same time, the date plate was also changed from the alternating red date/black date to a purely black date disc.
Rolex GMT-Master Ads
In the middle of the sixties the next conspicuous modification took place. The pointer tip for the 24-hour display changed: beginning as a small arrow tip, it became a larger tip. At about the same time Rolex changed the lettering on the dial from "SWISS" to "SWISS T<25". "SWISS" was during the time when radium was used as a luminous material for the dial and hands. With the switch to tritium, "SWISS T<25" was introduced to indicate the new luminous material.
Another eye-catching feature that makes today's GMT Masters (almost) unmistakable and missing from the first models is the date magnifier. This could be ordered at the time as an option, but was not compulsory for the model. The few copies without a magnifier are now a rarity. Most GMT Masters were supplied with a magnifier, despite the option. However, a glass without a date magnifier can be produced with a little effort from a glass with a magnifying glass. The original plexiglass from the time should be very rare and also due of the passage of time, the plastic is no longer practical, since with such old lenses their imperviousness to water can hardly be assured.
Around 1976, the movements were modified and the so-called "hack" function was added, a function which made it possible to stop the second hand in the time setting position to a to allow precise to-the-second adjustment.
GMT Master 16750
In 1981 there was a major modification and the GMT Master received a new movement, the caliber 3075 with mit 28800 bph. This clockwork has a "Quickset" (fast adjustment of the date), which is very handy, if you do not wear the watch very often. This major modification gave the GMT Master a new reference number, 16750. This model was still equipped with a Plexiglass lense, but had a shiny dial in contrast to the earlier GMT Master watches. The hour markers on the dial are pure tritium.
Beginning in 1986, the 16750 received a further modification and the indexes were edged with white gold, as with other models. The first white gold edged dials have one more special feature: Instead of the inscription, "Oyster Perpetual Date," only "Oyster Perpetual" is written on the dial and "Date" is missing.
The 16750 was produced for only 7 years (until 1988) and therefore isn't found that often. This makes the 16750 a highly sought-after model for collectors.
GMT-Master II 16760
In 1984, the next generation of the GMT Master, the GMT Master II with reference number 16760, was introduced. This GMT Master is lovingly called "fat lady," which is due to the new thicker case and the stronger crown protection. The new caliber 3085 was now able to move the 24-hour hand in 1-hour jumps forward or backward, without affecting the minute or second hand, a very practical thing. In addition, the GMT-Master II now had a sapphire crystal, the bezel was only available in black/red ("Coke"). The GMT Master 16750 was not replaced, but the GMT Master 16750 and the GMT Master II 16760 were offered in parallel until 1988/1989.
GMT-Master 16700 / GMT-Master II 16710
The GMT-Master 16700 with sapphire glass and caliber 3175, as well as the GMT-Master II 16710 with caliber 3185, were released in 1989. At the same time, the GMT-Master II was offered for the first time in steel/gold and gold (references 16713 and 16718). The steel/gold and gold models of the GMT Master (16753 and 16758) offered thus far were discontinued , and the GMT Master was now only available in steel. During the production period, the luminous material changed from Tritium to Superluminova in 1997. The GMT Master was offered in addition until the year 2000 and then discontinued in favor of the GMT-Master II 16710.
GMT (Ref. 16700)
The GMT Master II 16710 became available in three different aluminum bezel inlay variants: red/blue, black and red/black. The bracelets available were the Oyster bracelet (reference 78360) and the Jubilee bracelet (reference 62510). Very soon after their introduction, the Oyster bracelets were given the famous Oyster-Lock (fliplock). The reference number changed to 78790.
Throughout 16710 production, there were many more model upgrades, e.g.:
The luminous material changed from tritium to Superluminova around 1997.
"Solid End Links" were added to the bracelet and the holes in the lugs were removed (2000).
The paper guarantee certificates were replaced by plastic cards.
In 2007, the GMT-Master II got the new caliber 3186 with the Parachrome-Blue hairspring (M and Z serial numbers).
There were numerous dial variants ("Stick Dial," "Rectangular Dial," etc.).
GMT-Master II 116718LN
At the 2005 fair in Basel, there was a major new update with a completely new design. In 2005, two new GMT models were presented in solid gold, which had a new, significantly larger case, a new ceramic bezel with massive numbers and a new, larger crown. In addition, the new models again had a new, improved caliber (cal. 3186). The reference number was now 116718LN (Lunette Noir), named the normal "new" GMT and the 50th anniversary model with green dial.
New GMT in Steel (Ref. 116710)
Picture: Rolex
GMT-Master II 116710
In 2006, the steel/gold model followed in Basel and the steel model with reference number 116710LN followed in 2007. The bezel is so far only available in black. The term "LN" in the reference number indicates, however, that there should be further colored bezels (eg black/red or blue/red) in the future.
As expected from the patent documents, it was only a matter of time before Rolex offered a GMT with a two-color bezel. While there were still difficulties in the design of the ceramic inlay for the two colors, it was still at Baselworld 2013. But to the surprise of all the bezel was not black/red or red/blue as with the old models, but black/blue. The GMT hand was also dyed blue. The model now has the reference number 116710 BLNR (Blue & Noir, nickname "Batman"). Will there no longer be a red/blue GMT, which until now was lovingly called "Pepsi?"
However, a year later at Baselworld 2014 it was time. The hotly awaited GMT-Master II with blue/red bezel was presented. But here again, there was a stunning surprise, because this model was available exclusively in 18kt white gold and bore the reference number 116719 BLRO (Blue & Rouge).
At first, it was assumed that the new "Pepsi" GMT would most likely only be offered as a white gold model, as a steel GMT would be too similar in appearance. In addition, the blue/red bezels were supposed to be difficult to produce, so that they could only be manufactured in small quantities. But far from it:
At Baselworld 2018, GMT was updated with the new GMT model in steel (nicknamed Oystersteel), with reference number 126710. The GMT gained a slightly different/slimmer case shape – the case looks sharper and the lugs run more pointed. Instead of the Oyster bracelet, the GMT is now exclusively delivered with a Jubilee bracelet and inside, the caliber 3285 now works with 70 hours power reserve and a guaranteed deviation of less than -2/+2 seconds.
The GMT with the black bezel (116710 LN) was completely discontinued with the model change and will not have a successor. In addition, there is now the GMT-Master II in steel with a blue/red bezel (126710 BLRO); after 11 years, the 16710 has finally been given a legitimate successor.
The Rolex GMT-Master is an icon. It is probably the most famous "travel watch" in the world. The multicolored bezels make it unique and immediately recognizable within the Rolex range. No matter which model, each has its charm and a Rolex GMT-Master "somehow" belongs in every watch fan's collection.
The prices are rising quickly and significant 4-digit amounts are now being demanded, even for "simple" faded aluminum bezels. So if you want to own a GMT Master, you can't go wrong buying it now, rather than later.
Fidel Castro & Che Guevara wearing Rolex GMT-Master watches
(Photographers unfortunately unknown)
Years of construction
To conclude, here is an overview of the construction years of the models: