amanico[JLC Moderator]
400951
Vulcain Nautical Vintage Ref 2321. Another icon from the universe of vintage diving watches.
If it is not the first alarm diving watch ( see the JLC Deep Sea Alarm released two years before, in 1959 ), it certainly is one of the icons, and it was more famous than the JLC before its re edition!
42 mm super compressor case, decompression scale, alarm.
Credit picture: Antiquorum.

The only issue? Finding an all correct one. Most of them have changed crowns and hands.
A true challenge to find one.
Best,
Nicolas