Seiko G757 5020 Sports 100
The Seiko G757 Sports 100 watch is used by Bond (Roger Moore) in Octopussy. The Seiko is equipped with a tracking device to locate the Fabergé egg, and is clearly visible several times in the movie: first in Q's lab (Bond is already wearing the watch before Q explains what it can actually do), and later it is used to track the Fabergé egg.
This watch is very sought after and rare. Beware of sellers on eBay offering similar Seiko models, claiming it to be the Bond watch, but there is only one, and that is the one pictured here, the Seiko G757 5020. Look for the version with black 'horseshoe' (the shape around the digital screen) and metal band.
Buyers should watch out for the wording SPORTS 100 on the black bezel. There is a model G 757-5000 available with Silverwave wording on the black bezel. The shape is all the same, except the Silverwave wording and a slightly different LCD display.