The Fifty Fathoms with the small dial, in gold.

The 1953 Fifty Fathoms was built for French combat divers: a big luminous dial, a locking rotating bezel, a screw-down crown and 91 metres of water resistance, fifty fathoms. The Bathyscaphe of 1956 was the same idea in a case a civilian could wear to work, with a smaller dial and plainer markers. Blancpain revived the name in 2013 and it has become the Fifty Fathoms most people actually buy.

The gold version keeps everything that makes the watch a diver. The bezel is ceramic with markers in Liquidmetal, an amorphous alloy bonded into the ceramic so it cannot fade; the caseback is sapphire; the 1315 inside runs five days on three barrels and uses a silicon balance spring that ignores magnets. The red gold and the black canvas are the only concessions to dry land.

This is a regular Amazon listing from an independent dealer, Luxor Watches on the day we read it, with Amazon’s 30-day return window; it is not a Luxury Stores pre-owned unit. The second button opens the live search for gold Bathyscaphes in case this one has sold.

Fifty Fathoms Bathyscaphes have resold for under new and close to what pre-owned buyers paid, sometimes more, sometimes less; that is a pattern, not a promise, and nothing here is investment advice.