
2021 Blancpain Fifty Fathoms Bathyscaphe
A Fifty Fathoms with an exquisite blue sunburst dial, a ceramic bezel, and the Blancpain 1150 automatic movement.
Overview
Widely regarded as the first modern dive watch, the Blancpain Fifty Fathoms holds a significant place in the history of horology. Its origins can be traced back to the early 1950s when Blancpain’s then CEO, Jean-Jacques Fiechter, collaborated with French naval officers Bob Maloubier and Claude Riffaud to create a watch that could withstand the rigors of deep-sea diving while ensuring precise timekeeping and excellent legibility. In 1953, Fiechter delivered a watch that fully met their testing criteria—the Blancpain Fifty Fathoms.
Named after the depth at which it could be submerged, the Fifty Fathoms featured several groundbreaking innovations including a robust watertight case made of stainless steel, a unidirectional rotating bezel with clear markers for timing underwater dives, and a highly legible dial with luminescent hands and hour markers. These features ensured that divers could easily read and measure elapsed time accurately, even in low-light or murky conditions. Furthermore, the Fifty Fathoms boasted an automatic movement, which eliminated the need for manual winding and provided additional convenience and reliability for divers.
After the initial release, Blancpain continued to refine and innovate the Fifty Fathoms collection to meet the needs of its wearers, which included the French Navy, the U.S. Navy, and Jaques Cousteau's famed Calypso divers. Notably, in the late 1950s, a slightly smaller and more civilian-oriented version of the original Fifty Fathoms was introduced—the Bathyscaphe. It offered a sleeker 35mm to 38mm profile for everyday wear while maintaining the core characteristics of its predecessor.
Many years later, in 2013, Blancpain released a re-interpretation of the Bathyscaphe in a 43mm case. While the watch was well-received, the chief complaint was about its size and the brand eventually released a 38mm version in 2017 that was more in line with the ethos of the original. Available in either white, black, or a stunning “abyss blue”, the 38mm Bathyscaphe featured several luxurious adornments including a Liquidmetal ceramic bezel, a sunburst dial with jewel-like hour markers, and an automatic movement with a whopping 100-hour power reserve and an 18K gold rotor. The smaller size has served the brand well and is now more tasteful than ever as dive watches such as the Tudor Black Bay 54 return to vintage proportions with much fanfare.
Specifications
Brand:
Blancpain
Model:
Fifty Fathoms Bathyscaphe
Reference:
5100-1140-O52A
Year:
2021
Case Number:
No. 1131
Case Material:
Stainless steel
Diameter:
38 mm
Lug Width:
20 mm
Thickness:
10.8 mm
Lug-to-Lug:
44.0 mm
Dial:
Blue
Lume:
Super-LumiNova
Crystal:
Sapphire
Movement:
Automatic
Caliber:
Blancpain 1150
Bracelet/Strap:
Blancpain blue textile strap with tang buckle
Max Wrist Size:
Hand model has a wrist size of 6.1 in
Condition
Case: The satin-brushed case shows hardly any signs of wear with only a couple extremely faint hairlines on the case sides. The lugs are beautifully faceted and impeccably sharp. The ceramic bezel is in flawless condition. The caseback is super clean and shows virtually no signs of wear. The model and serial number engravings are crisp and deep.
Dial, Hands, & Crystal: The blue sunburst dial and polished hands are in perfect condition with fully functioning Super-LumiNova. Both front and rear sapphire crystals are squeaky clean and scratch-free.
Bracelet/Strap: The Blancpain blue textile strap shows minimal signs of wear. There is some very light fraying at the lugs, probably due to how sharp they are. The buckle has a tiny scuff on one side.
Performance
Functions: All functions including the crown winding, time setting, and quickset date are working as expected.
Service History: None.
What’s Included

What’s Included
Watch
Blancpain Fifty Fathoms Bathyscaphe on a blue textile strap.
Box/Papers
Boxes, instructions, service booklet, diver's logbook, and guarantee dated October 2021.
Extras
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Authenticity Guarantee
Each watch is thoroughly evaluated and guaranteed to be authentic unless explicitly stated otherwise. Prior to any sale, we are happy to provide additional photos or videos of the watch, movement, and accessories at your request. Once you receive the watch, we allow a 72-hour inspection period during which you may return the watch for a full refund if it is misrepresented.
We spend a considerable amount of time researching any watch we plan to source. This includes cross-checking the visual details, case numbers, and movements using examples sold by other reputable dealers and buying guides published by subject matter experts. We set very high standards and will not consider any watch with questionable parts or inconsistencies that cannot be verified elsewhere.
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All watches, regardless of their value or destination, ship for free using an expedited service with signature confirmation. We can deliver to over 80 countries outside of the United States, including most major markets. Please contact us prior to purchase to confirm that your country is available for international shipping.
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Condition Grades
We use the following rubric to assign each watch a condition grade that best represents its external appearance.
Timegrapher Readings
These readings were taken on a Weishi No. 1000 timegrapher approximately one hour after fully winding the watch.

























