Blancpain can boast a long history of providing divers’ watches for military units since its introduction of the original Fifty Fathoms in 1953. By the mid-1960s, Blancpain was producing a version of that seminal timepiece to the elite combat swimmers (“Kampfschwimmers”) of the German Navy, one notable for the use of a red-and-yellow “No Radiations” logo on its dial. The emblem indicated that the watch’s luminescent details were not composed of radium, a radioactive material that had previously been used regularly in watchmaking but by the early ’60s had been declared harmful.

The Tribute to Fifty Fathoms No-Rad replicates a military model from the 1960s.

This Fifty Fathoms RPG-1, or so-called “BUND No-Rad” model from 1963 (“BUND” referred to the German “Bundeswehr,” or armed forces), provides the inspiration for the new Tribute to Fifty Fathoms No-Rad Limited Edition. Housed in a 40.3-mm-diameter polished steel case, a size reserved exclusively by Blancpain for its Fifty Fathoms limited editions, the watch replicates many of its vintage forebear’s recognizable elements. Chief among them is the aforementioned colorful disk above 6 o’clock, whose red segments on a yellow background was designed as visual shorthand to assure the watch’s users ? military as well as civilian ? that the timepiece was radiation-free and not hazardous to wear for long periods as were its radium-t...