Rolex’s GMT Ventures
Just about any aspect of modern culture you can name has a ‘golden’ era: the window between establishing its presence in our lives and being taken for granted. For commercial aviation, that era spanned the two decades after World War II, when innovations such as jet-propulsion made transcontinental air travel much quicker and safer, but still inaccessible enough to maintain an aura of luxury, status and magic.
Frequent air travellers of the time found themselves in need of a watch that could track multiple time zones. Rolex was one of the companies that obliged. When Pan American World Airways — commonly known as Pan Am — decided to equip its pilots with such a piece in the 1950s, they approached the Swiss watchmaker. The GMT-Master was the fruit of that collaboration.
And an incredibly resilient one, as it turns out. It has gone through numerous iterations, and even outlived the company that originally commissioned it. It is quite remarkable that, in our digital era, the omnipotent and ubiquitous smart-phone seems unable to dig the grave of this decidedly analog piece of engineering from the twentieth century.
The diversity of GMT-Master references is staggering. Keeping track of all the variation — complications, dial text, colour and texture, luminous material, lume-plot size, bezel colour and material, precious-metal variants, reference nicknames — might be enthralling for watch geeks, but bewildering for novices. Here are brief descriptions of two notable references that will serve as an introductory guide for the perplexed.
Reference 6542
The story begins here. Produced between 1955 and 1959, the 6542 has bequeathed its design DNA to all subsequent GMT-Master references, and set a template for GMT watches in general. It features the iconic bi-directional, 24-hour graduated, red and blue bezel that gave it the ‘Pepsi’ moniker. Its fourth 24-hour hand completes one revolution per day and is slaved to the 12-hour hand. The Oyster steel case is 38 mm in diameter. It has a gilt dial, a chapter ring, a cyclops date magnifier, a Mercedes handset, and 50 meters of water resistance. ‘Officially Certified Chronometer’ (OCC) is written above the 6 o’clock position. Radium supplies the luminescence. Three different automatic movements powered the first GMT-Master reference: calibres 1036, 1065 and 1066.
The bakelite bezels were recalled due to their tendency to crack; concerns over radioactivity were also a factor. Rolex replaced them with anodised metal bezels without luminescence, making bakelite examples of the 6542 extremely rare and — naturally — highly coveted by collectors.
In late 1958 a revised version of the 6542 featured enlarged lume plots that sat closer to the indexes of the chapter ring.
To monitor a second time zone, the wearer can adjust the bezel. For example, at 11 AM in Los Angeles the slaved GMT hand reads 11:00 against the bezel. To keep track of the time in, say, New York, which is three hours ahead, the wearer can rotate the bezel three clicks counter-clockwise, such that the GMT hand reads 14:00 (2 PM) against the bezel.
Reference 16760
Produced between 1982 and 1988, this is the first GMT-Master II reference. Calibre 3085 gives it the ability to adjust the GMT hand independently of the 12-hour hand. The latter is now able to jump 1-hour increments without stopping the watch; jumping it past midnight also changes the date. This ability came with a visible increase in the thickness of the stainless-steel case, which, along with the beefy, rounded crown guards and the wider bezel, gave the watch its ‘Fat Lady’ nickname.
This is also the first reference that features the red and black aluminium ‘Coke’ bezel. It also has a sapphire crystal, its case diameter is 40 mm and its water resistance is rated at 100 meters. The luminescent material is tritium. The dial is glossy and has ‘Superlative Chronometer Officially Certified’ (SCOC) written above the 6 o’clock position. The date cyclops is present but there is no chapter ring on the dial.
GMT-Master II references give the wearer the ability to track one time zone with the 12-hour hand, a second time zone with the independently adjustable 24-hour hand, and a third time zone by offsetting the bezel by an appropriate number of clicks — clockwise rotation goes backward in time, counter-clockwise rotation goes forward in time.
For example, a person from Los Angeles travels to New York and wishes to monitor the time in Paris. At 11 AM in Los Angeles, the wearer can set the 24-hour hand to correspond to 11:00 on the bezel; that is the ‘home time’ or ‘reference time’. Then, the local 12-hour hand is set at 2 PM, giving the time in New York. To monitor the time in Paris, the bezel is rotated against a known offset from the reference (GMT) hand. If Paris is eight hours ahead of Los Angeles (depending on daylight savings), the bezel must be rotated 8 clicks to the left of the GMT hand, which now reads 19:00 (7 PM) on the bezel.
Interesting fact: Rolex did not retire the GMT-Master until 1999, almost two decades after the introduction of the GMT-Master II.