Audemars Piguet Royal Oak Offshore 26421ST.OO.A002CA.01

Audemars Piguet usually reserves the tourbillon for precious metal, so a steel Offshore carrying one is the exception rather than the rule. This 2019 Audemars Piguet Royal Oak Offshore Tourbillon Chronograph, reference 26421ST.OO.A002CA.01, pairs the brand's most demanding complication with its most casual case.

The case is 45mm stainless steel with the Offshore's octagonal bezel and eight exposed hexagonal screws. The crown and chronograph pushers are black ceramic, a material choice that distinguishes this reference from the earlier steel Offshore tourbillons. It is mounted on a black rubber strap.

The dial is skeletonized, so the bridges and mainplate of the movement take the place of a conventional dial. The tourbillon carriage is set at six o'clock with the chronograph counters at three and nine, and the hands and applied hour markers are filled with luminous material for legibility against the open architecture.

Inside is the manually wound caliber 2947, a column-wheel chronograph with a one-minute tourbillon and a power reserve of roughly 65 hours. The movement was designed to be viewed from both sides, which is why the openworked dial exists at all; the finishing on the bridges is the dial.

This example is offered pre-owned. The seller reports light scratches on the bezel and hairline marks on the case, consistent with regular wear of a brushed steel sports case. No service history was disclosed by the seller.

The watch comes with its presentation box and an extract from the Audemars Piguet archives, which records the original production details for this serial number. The original warranty papers are not included, and the seller has provided no further account of the watch's history.