GMT Master, Orig. in 1954 or 1955?
 

I've been reading various sources and many say that the GMT Master originated in 1954. However, Rolex's advertising (an example of which is quoted in my signature below) states that it originated in 1955.

I've tried searching but can't seem to find the answer to this discrepancy. My theory is that while the movement and case originated in 1954, it was then called the Turn-O-Graph and wasn't called the GMT Master until after Pan Am and Rolex collaborated and released it by that name in 1955. Anyone know for sure?

I don't know for sure...

But my Rolex GMT Master iPhone App states that the 6202 Turn-O-Graph with 24-hour complication came out in 1954. The 6524 is also listed as having been introduced in 1954.

For whatever that's worth...

This site:

http://gmtmasterhistory.com/gmt-master_ref_6542.html

States the following:

Production Period: 1954-1959
Model Name: Rolex GMT Master
Caliber: 1036 (1954-1959), 1065 (1957-1959), 1066 (1957-1959)
Pressure proof to 50m/165ft

This was the first GMT Master.
It was launched 1954. It was developed on the basis of a regular Turn-O-Graph (Ref. 6202). The modifications were a different bezel and a modified movement.

Extract from a Rolex Dealer card dated about 1995 :

1953 - Explorer
1953 - Sub no date
1954 - GMT
1970 - Sub date
1971 - Sea Dweller
1972 - Explorer 2
1983 - GMT 2
1992 - Yacht Master

I would say 1954

http://i235.photobucket.com/albums/e...s/ec978f19.jpg


Warning this is according to "Tourneau" :thumbsdow