The Rolex GMT was designed as an aviator watch: The newly introduced fourth hand allowed the display of an additional time, with the corresponding numbermarkings on the outer bezel. Pilots used the second time to display the Greenwich Mean Time (GMT), which led to the name Rolex GMT Master. Altough Greenwich Mean Time (GMT) got replaced 1972 in the Aviation Industry by Coordinated Universal Time (UTC), the term GMT is still known and kept as part of the name of the GMT Master, altough Pilots nowadays use it to set UTC.
The Rolex GMT Master was developed in cooperation with Pan Am. As in the 1940s and 50s flying distances got longer and the pilots travelled through multiple time zones, Pan Am asked Rolex in the 1950s to develop a watch which could tell different times simultaneously.
The first GMT (Ref. 6542) was a regular Turn-O-Graph (Ref. 6202) with a different bezel and a modified movement.
(Source: GMT Master History)
Production Period: 1989-2007
Model Name: Rolex GMT Master II
Caliber: 3185 (late models with 3186), 28800A/h, hacking, quickset (24-hour-hand)
Pressure proof to 100m/330ft
Bracelet: Oyster 78360 and 78790 (Oysterlock), Jubilé 62510
Glass: Sapphire crystal
Bezel: Anodized aluminum, 120 clicks
Tritium (until 1997): T<25 dial
Luminova (1998/99): Swiss dial
Superluminova (2000-2007): Swiss made dial
The Ref. 16710 replaced 1989 the Ref. 16760 featuring a new, but identical functioning caliber and a slimmer design.
Variant: Luminova on a T<25 dial (1998)
1997/2000: Tritium -> Luminova -> Superluminova
2000: Solid end link bracelet indroduced (SEL).
2003: Laser crown introduced.
2003: No holes case starting (late Y-series).
2007: New certificate (plastic/credit card size) introduced (Z-series).
Late 2007: Caliber 3186 instead of 3185 (late Z-series and the M-series).
Available with three different bezels:
Red/Black aka Coke (Bezel 315-16760-7)
BLRO, Blue/Red aka Pepsi (bleu/rouge), (Bezel 315-16700-6)
LN, Black (lunette noire), (Bezel 315-16700-1)
Ref. 16713 steel/yellow gold aka Tigerauge (Eye of the Tiger) (Bezel: 315-16713-5 or 315-16718-1); Oysterbracelet 78363 and 78793 (Oysterlock), Jubilébracelet 62523
Ref. 16718 yellow gold (Bezel 315-16718-3); Oysterbracelet 7206/8 and 78798 (Oysterlock), Jubilébracelet 8386/8