Cornavin P810 Dive Watch

This is a rare and historically important  dive watch manufactured by Cornavin, a small Swiss watch manufacturer in the 1950's .  It is referred to as a P810 and is known for its unique decompression dial.  The original black dial shows a decompression table marked up to 40 meters with intervals for divers to use as guidance for safe returning to the surface.  The dial also displays a Jump Hour aperture instead of a traditional hour hand.   The watch's  42mm case size is impressive for a watch from this era.   This condition of this rare dive watch is impressive since these were tool watches  and used.