The Rolex GMT-Master

The Rolex GMT Master

The Rolex GMT-Master is a professional line of watches and part of the Rolex Oyster Perpetual collection. Named after “Greenwich Mean Time”, it was designed specially for pilots. Although its place has been taken over by its successor GMT-Master II, which features improved functionalities, the early models of GMT-Master are still sought after by watch collectors all over the world. Like other Rolex specialty watches, this model has a fascinating story behind its creation.

What Led to its Development?

In the early 1950s, Rolex was approached by Pan American Airlines. They inquired whether Rolex could produce a special watch that could display the time in two different time zones simultaneously. The request was because their pilots had to travel through multiple time zones. In response, Rolex came out with the first model 6542 of GMT-Master in 1954. It had a special 24 hour hand and a bi-directional rotating bezel that were designed to give the time in any two time zones at the same moment. Since it worked exactly as ordered, it soon was adopted by other airlines as well.

Features of the Earliest Version

The earliest version (Model 6542) featured an acrylic Bakelite bezel with a dark finish. This finish was to ensure that the bezel did not reflect into the pilot's eyes while he was flying the airplane. However, today it is almost impossible to find such a model with this original bezel as it was replaced with a metal bezel soon after the initial launching. This stylistic change was made because the original bezel could not withstand the warm climatic conditions. Another feature of the earliest version was that it sported a depth rating of 165 feet, emblazoned in red color, on its dial and not the name “GMT-Master.” In addition, none of the early versions used the Cyclops lens that was usually placed over the date aperture.

The earliest versions of the GMT-Master also were made available in two dial colors: white and black. It is intriguing to note that this dual color option actually was requested by the Pan American Airlines because they wanted black dial GMT-Master wristwatches for the air crews and the white dial for the ground staff.

Improvements Included Over the Years

In the early 1960s, changes were introduced in the Rolex GMT-Master such as a shift in the color of printed letters on the dial from gold to white. In addition, the color of the date wheel numbers was changed from alternating red/black to all black. By the mid 1960s, the arrow on the tip of the extra 24-hour hand was enlarged. Like in other Rolex watches of that period, in this model Tritium was introduced as the luminous material in the dial and hands, in place of Radium. In the 1960s, the model 1675 had been added with a crown guard. In the same model, "Superlative Chronometer Officially Certified" appeared in place of "Official Certified Chronometer."

The early 1970s also saw certain significant changes being introduced into the various models of Rolex GMT-Master. For instance, the model 1675 was launched, this time with a jubilee bracelet and a bezel fitted with a black insert. The hack feature was added to the model 1675 in 1976. This feature aimed at simplifying the time setting procedure wherein the second hand stops as soon as you unscrew the crown and pull it out to set the time.

In 1981, the model 1675 was fitted with the new 3075 movement and was re-numbered as the 16750. The "Quick Set" feature was also added to it. A new model, called GMT-Master II (Model 16760) was introduced in 1983 that featured a sapphire crystal. In addition, it was powered by the new 3085 movement. Subsequently, the 16750 model was replaced by the 16700 GMT-Master featuring the 3085 movement. It was available only in stainless steel. In 1987, it was fitted with the sapphire crystal.

GMT-Master: Working as a Time Zone Specialist

The special 24-hour bezel is divided into two equal parts: the time 6:00 to 18:00 in red representing day while the time 18:00 to 6:00 in blue or black representing night. In some models, this division is represented by two different colors. The special 24-hour hand is used to appropriately display the 24-hour time on the bezel. For instance, if the 24-hour hand is pointing to 10 on the red portion of the dial, it means 10:00 AM. On the other hand, if it is pointing to 22 on the blue (or black) portion of the dial, it means 10:00 PM. Now, suppose it is 10:00 AM in the Eastern Time Zone. We already known that the Pacific Time Zone is 3 hours behind the former. Therefore, to indicate the correct time in the Pacific Time Zone, one simply turns the bezel until three hours forward. This means the hour and minute hands now indicate 10:00 AM while the special 24-hour hand indicates 7:00 AM.

The Rolex GMT-Master was an instant hit in the market, even though it had been specially requested by and designed for aviators. The early versions of this model are valuable vintage collectibles. The modern versions remain in demand all over the world.