Audemars Piguet Royal Oak Tourbillon 25831ST

A Salmon-dial AP is special, but one with a Tourbillon to celebrate the 25 year anniversary of the Royal Oak is something else.

While the Royal Oak was already beginning to be viewed as a design icon in 1997, it hadn’t yet entered the rarefied category of truly legendary watches. To mark the occasion, Audemars Piguet quietly released an extremely limited and truly exceptional line-up of watches. The thing that makes the ref. 25831 so special is that it was the first ever Royal Oak to incorporate a tourbillon complication.

The tourbillon was invented by master watchmaker Abraham-Louis Breguet in 1795. By suspending the escapement and balance wheel—the central parts of a mechanical watch movement—in a rotating cage, this ingenious mechanism can dramatically reduce the effects of gravity and thus improve the accuracy of a watch. Today, the tourbillon mechanism is considered one of the ultimate tests of a watchmaker’s technical prowess and superior finishing techniques.

The ref. 25831 was produced in an extremely limited series, spread over 4 metals; excluding a Pièce Unique in bicolor for the Sultan of Brunei. 25 Of them being released in stainless steel, at the time the most expensive stainless steel watch ever, just like the original Royal Oak was. The case has a peculiar, yet mesmerizing, symmetrical design to the inclusion of a hidden crown on the caseback. It is not a "backwinder" since it is in fact an automatic movement: Cal. 2875. Also displaying a 52H power reserve and the date.

Besides the various metals there were also numerous dial options. The most coveted obviously being the Salmon dial. This exquisite example features Audemars Piguet’s iconic ‘Petite Tapisserie’ engraved pattern. The time can be read on a charming miniature dial at the 12 o’clock position, while two smaller sub-registers at 3 and 9 display the previously mentioned functions. All 3 subdials have smooth surface instead. A large cutout at the 6 o’clock position reveals the central part of the watch: the tourbillon cage, itself creatively surrounded by a miniature Royal Oak bezel.

This ultra-collectible 25831 is in exquisite condition. A steampunk design marvel by Emmanuel Gueit, the founding father of the Offshore but also so much more.