There are few watches which offer a decompression scale for divers: The Vulcain Nautical is the most famous. The Mido Powerwind is the other one, less known, of course, but with a lot of charm. Here is a picture I took some 5 years ago, of a quite NOS mod...
... I wonder how practical this dial could be to plan a dive before getting into the water, but from the watch collectors´s point of view it is a wonderful piece! Thank you for sharing with us! I´d love to have one in my collection of course! Un abrazo mi...