amanico[JLC Moderator]
399994
An UFO in the vintage diving watch universe: Nivada Grenchen Depthomatic.
There were two " Depthomatic " from Nivada Grenchen, one from 1964, and the second generation, from 1966.
Here is the second generation.
This watch, water resistant to 200 meters, is a mechanical depth gauge, and it seems that the first generation from 1964 is the first one to offer such a tool. The most famous Favre Leuba, the Bathy 50, is from 1966.
Enjoy.
Nicolas