The first modern dive watch, in gold and blue.

Fifty fathoms is about 91 metres, the depth Blancpain’s 1953 watch was built for, and the name stuck to every version since. The rules the original set, a bezel that only turns one way so a knock can only shorten your dive, a crown that screws down, hands and markers you can read in the dark, became the rules for every dive watch after it. The Automatique is the direct descendant, at the original’s scale rather than the smaller Bathyscaphe.

The bezel is the part to look at. Instead of an aluminium or ceramic insert, Blancpain uses a domed sapphire crystal with the markers underneath it, so the scale sits under a glossy blue curve that catches the light like the crystal over the dial. In red gold with a blue dial and strap the watch is two colours and nothing else, with the cream luminous paint doing the reading.

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 Fifty Fathoms in case this one has sold.

Fifty Fathoms 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.