Blancpain re-interprets one of its vintage pieces from the 1950s, the Fifty Fathoms with a water-tightness indicator.

The history of the Fifty Fathoms brings together two lineages. First is that of Jean-Jacques Fiechter a passionate diver who was Blancpain’s CEO for three decades, 1950-1980. The second is that of Captain Robert “Bob” Maloubier and Lieutenant Claude Riffaud, founders of the French Navy’s combat swimmers corps and who were searching for a reliable watch for their underwater missions.

In the early 1950s, Jean-Jacques Fiechter was a sport diving pioneer. Based on his personal underwater experiences, he came to understand that a diver’s life depended upon a reliable timekeeping instrument and he saw that none existed in the marketplace. As head of Blancpain, he tasked his watchmaking team with addressing the challenges of measuring time in the underwater environment. The first criteria was obvious: water resistance. To solve the problem, he set about conceiving a double sealed crown system. Without a screw holding down the crown, this served to protect the watch from water penetration in the event that the crown were accidently to be pulled during a dive. The presence of the second interior seal worked to guarantee the timepiece’s water tightness. Jean-Jacques Fiechter registered a patent for this invention. A second patent was awarded for the sealing system for the caseback. This had indeed been a recurring problem with other pre-existing systems because of the way in which the “O” ring, used to seal the caseback, might become twisted when the back was screwed into the case. In order to eliminate this risk,

Fiechter invented a channel into which the “O” ring would be inserted and held in position by an additional metallic disk.

He then addressed another problem: a secured rotating bezel that could be used to measure the time of a dive. His idea was to rotate the bezel so as to place its zero index opposite the minutes hand. In this way, the diver could read the passage of time while underwater using the minutes hand to read markings on the bezel. Here too, security was front and center in Fiechter’s thinking.

Any accidental movement of the bezel could induce a timing error with dramatic consequences. Fiechter therefore perfected a blocking mechanism which would prevent accidental rotation of the bezel. For this he received another patent. Later, Blancpain introduced a uni-directional rotating bezel, a world-first feature which also ensured safety during a dive.