Editorial
The 42mm Fifty Fathoms Automatique is the version collectors quietly prefer. It wears like a proper dive watch without the wrist presence of the 45mm that dominates the catalog. Same depth rating, same movement, easier daily use.
The Fifty Fathoms line traces to 1953 and the original tool diving watch Blancpain built for the French military. The modern Automatique family reinterpreted that heritage for contemporary collectors, with the 45mm leading and the 42mm following as the smaller option. Reference 5015-1130-52 represents the steel, sapphire-bezel configuration in the 42mm format.
Blancpain has offered both sizes concurrently, but the 42mm has always been the quieter seller, which makes it less visible at retail and on the secondary market. The textile strap and bracelet configurations give owners flexibility that the 45mm shares, but the 42mm wears the proportions better on smaller wrists.
The 42mm is genuinely less common than the 45mm, so secondary market examples are harder to find and comparison shopping takes longer. Buyers sometimes conflate the two sizes in listings, so verify the reference number rather than relying on seller descriptions of size. The sapphire bezel on the 5015-1130-52 is scratch-resistant but not scratch-proof, and deep scratches are costly to address.
Early examples from 2007 to 2010 may have higher service mileage if they saw regular dive use. Blancpain authorized service is expensive relative to independent alternatives, and the 1315 caliber requires a watchmaker with genuine familiarity with the movement.
