The Fifty Fathoms was born from a real-world need. In the early 1950s, French Navy officer Lieutenant Bob Maloubier had been tasked with creating a unit of combat divers - the Nageurs de Combat. After testing Longines, Universal, and Rolex pieces and finding all of them wanting, he approached Blancpain in late 1952. By coincidence Blancpain CEO Jean-Jacques Fiechter was himself an avid scuba diver who had nearly run out of air on a dive in Cannes the previous summer because his watch had no reliable elapsed-time scale. The two men sketched the first specification together, and the Blancpain Fifty Fathoms was released to the Nageurs de Combat in mid-1953 - several months before the Rolex Submariner.
The design established every convention that would define the modern dive watch: a unidirectional rotating bezel (to prevent accidental resetting to a longer dive time), a high-contrast black dial with luminous indices, a double-sealed crown, a soft-iron inner cage for magnetic shielding, an automatic movement, and depth rating well beyond recreational limits (50 fathoms ≈ 91.45 metres). The name itself came from Shakespeare's The Tempest: "Full fathom five thy father lies" - five fathoms being the depth of the grave, fifty fathoms representing a depth no diver should expect to return from.
The Fifty Fathoms was adopted by the French Nageurs de Combat, German Kampfschwimmer, Israeli commandos, US military dive units (under the Tornek-Rayville TR-900 variant to satisfy Buy American Act rules), and others through the 1960s and 70s. Civilian interest exploded after Jacques-Yves Cousteau wore one in his 1956 Oscar-winning documentary Le Monde du Silence. The MIL-SPEC series (1957) introduced the characteristic moisture indicator at 6 o'clock, and the Bathyscaphe (1956) was the slimmer everyday version - both references still echoed in the modern lineup.
The modern Fifty Fathoms was reborn in 2007 under CEO Marc Hayek. Reference 5015 grew to 45mm, adopted a sapphire bezel insert (a serial-production first), and introduced the in-house Calibre 1315 - three mainspring barrels in series for a 120-hour (five-day) power reserve, silicon balance spring, and adjusted to five positions. The family now includes the Fifty Fathoms Automatique (45mm), Bathyscaphe (38mm and 43mm), Barakuda, Tech Gombessa (47mm Gombessa-certified), the tourbillon, and the Nageurs de Combat MIL-SPEC re-editions. 2023 marked the 70th anniversary with three commemorative 42.3mm pieces using the new Cal. 1315S movement.
