No other watch so immediately evokes the glamourous world of 1950s international air-travel as the Rolex GMT-Master. Advertised at the time as being “the ideal watch for air-pilots, ships’ captains, travelers and businessmen”, the GMT-Master has a fourth arrow-tipped hand for the display of a second time zone with corresponding 24-hour numerals on the bezel. The model was developed at the instigation of Pan American Airlines (Pan Am) who asked Rolex to produce a watch on which two time zones could be read simultaneously. Originally, pilots set the additional hand to Greenwich Meantime, hence the origin of the model’s name “GMT-Master”. The first reference 6542 was in production between 1954 and 1959. The distinctive red and blue bezel of this and later models has become nicknamed the “Pepsi” by collectors.
General
Dial
- Silver dial with tri color subdials
- Tritium indices
- Small seconds at 9 o’clock
- 12-hour counter at 6 o’clock
- 30-minute counter at 3 o’clock
- Date indication at 4:30
- Dial variations:
- A under H
- A offset to H
- Service dials
Case
- MK I: 9 mm
- MK II: 9 mm
- MK III: 10 mm
Tachymetre Scale
There are mostly two types of tachymetre scales can be seen, but I’ve also seen another one in years.
- The original and period correct tachymetre scale has a straight “C”
- The service tachymetre scale has a curved “C”
- The other service one has linear writing besides radial writing on tachymetre numerals and angular “C”.
Movement
- Hours and minutes in the centre
- Small seconds at 9 o’clock
- Tachymetric scale
- Date indication at 4:30
- Chronograph:
- Central chronograph hand
- 12-hour counter at 6 o’clock
- 30-minute counter at 3 o’clock
