This particular diver's watch, (the original model dates back to the mid-1960s), a version of which was part of the German Navy's Combat Swimmers' equipment, had the distinction of bearing the "no radiations" logo on the dial, indicating the fact that Blancpain did not use luminescent material containing radium. The distinctive mark on the dial of the watch made its fortune; the watch and its variants are now part of the most iconic Fifty Fathoms models, to which the new Tribute to Fifty Fathoms No Rad model pays tribute. The Tribute to Fifty Fathoms No Rad (produced in a limited series of only 500 pieces) is thus a reinterpretation of the aforementioned historical model. The matt black dial features geometric, circular, rectangular and diamond-shaped hour markers (at 12 o'clock). The hour circle, the hands and the scale on the bezel are coated with Super-LumiNova 'old radium', which reproduces the beige-orange hue that the patinated indices of the time displayed. At 3 o'clock, the date window is highlighted by a white frame, as on the 1960s models. The dominant element of the dial, however, remains the yellow and red 'no radiations' logo, which amplifies the already bold character of this timepiece. The unidirectional rotating bezel, with the scale typical of the Fifty Fathoms of yesteryear, is fitted with a sapphire crystal insert, an identifying feature of the collection. With its convex profile, it contributes to emphasising the appearance of the watch, which is already enhanced by the use of a sapphire crystal glassbox. The steel case, water-resistant to 30 atmospheres, has a diameter of 40.3 mm. Inside beats the Blancpain Calibre 1151, a self-winding movement equipped with a silicon balance spring and a power reserve of no less than four days. Its two barrels are wound by a rotor with a cartridge-shaped opening, a reference to some of the collection's historical timepieces, including the very first Fifty Fathoms. Atypical today, this detail once served to make the oscillating weight more flexible, to protect the movement against possible blows. The watch is fitted with a rubber strap of the "Topic" type, a material that was very popular with divers of the time because of its durability.
