Probably one of the most sought-after Breitling models is the Navitimer ref.806. However, not everyone (or every owner) knows how to use all the information on the dial in combination with the slide rule. Bill Sohne, a well known collector who’s active on the internet for years now, and Chuck Maddox (the ?ɬºber Chronograph-meister) put the original manual online of the vintage Breitling 806 Navitimer APOA.

It describes perfectly how to perform calculation with this watch, using the slide rule. Click here for the online manual.
Scan of the manual below by Bill Sohne and published by Chuck Maddox.