Hodinkee at http://www.hodinkee.com/blog/2009/7/...ce-watche.html posted this...

The Rolex GMT Master 1675: While we all know the Omega Speedmaster Professional was official NASA issue, it is widely held that Jack Swigert, of Apollo 13, was actually wearing a Rolex GMT on that fateful flight. That theory is half true. In actuality, Swigert wore his personal GMT under the sleeves of his space suit while he wore his Omega on the outside. Many people have wondered why the GMT wasn't used for the moon missions and there are two simple reasons. 1) It is an automatic watch, and the lack of gravity would affect the accuracy of the movement. 2) It lacks a chronograph, and unlike most of us, the Apollo Astronauts actually used their chronographs for very important things.

Although, a Rolex will wind without gravity as it is inertia originating from the wearers arm that makes the rotor move, not gravity...

There is also more posted at http://rolexblog.blogspot.com/2008/0...lex-story.html complete with all the commentary and opposing comments.

-Sheldon