A rare and very interesting vintage Blancpain Fifty Fathoms Rotomatic Incabloc.
According to the owner, and the former owner, this one was used by the French Marine Nationale. I knew they existed, but this is the first one I see in person.
You will notice the triangle at twelve,
And the early case number 6xx.
When watches have both character and history, they are simply irresistible.