Audemars Piguet Royal Oak Offshore: Diver, Chronograph, and How to Choose

The Offshore is where Audemars Piguet stopped asking for permission. Three decades later it has quietly become the most wearable serious AP you can buy.

In 1993 Audemars Piguet released a 42mm version of the Royal Oak with an exposed rubber gasket around the crystal, oversized pushers, and a case thick enough that the watch was immediately nicknamed The Beast. It was designed by a young Emmanuel Gueit, and the reception was not warm. Gérald Genta, who had designed the original Royal Oak, is widely reported to have been unimpressed.

The watch that was too big for 1993 is now, by the standards of everything that followed it, entirely reasonable. And in the years since, the Offshore has done something the standard Royal Oak has not: it has stayed buyable. You can acquire a serious Offshore without a purchase history, without a list, and without the surrounding theatre.

Reading Audemars Piguet references

The pattern looks intimidating and is not. Take 15720ST.OO.A052CA.01.

The Diver: 15710 and 15720

Introduced in 2010, the Offshore Diver is 42mm, water resistant to 300 metres, and carries an inner rotating dive bezel operated by a second crown at ten o'clock. That inner-bezel arrangement is what makes it work as a design: the case retains the clean Offshore silhouette because the dive functionality is hidden inside it.

It is also, in my view, the most quietly correct watch Audemars Piguet currently makes. It has the Royal Oak DNA — the octagonal bezel, the eight hexagonal screws, the integrated case — in a package you can wear to dinner or into the sea without thinking about it.

15710 versus 15720

In 2021, AP replaced the 15710 with the 15720. The changes are more significant than the reference number suggests:

• The dial. The 15710 used the "Méga Tapisserie" pattern — large squares. The 15720 moved to a smaller, more refined tapisserie, which changes the character of the watch considerably in person.
• The movement. The 15710 used AP's calibre 3120. The 15720 introduced a newer in-house automatic. Both offer around sixty hours of reserve; the newer calibre is the more current architecture.
• The finishing. The 15720 refined case and bracelet detailing.

15710ST.OO.A002CA.01 in black is the classic execution and the one most people picture. 15720ST.OO.A052CA.01 in khaki green is the newer generation in a colour that has aged far better than the 2021 colour trend it arrived in — it reads as olive and military rather than fashionable, which was not obvious at launch.

The Offshore Diver has the Royal Oak's entire design language in a watch you can wear into the sea without a conversation about it. That is a rarer proposition than it sounds.

The 44mm Chronograph: 26400 and 26405

This is the Offshore in its fullest expression. 44mm, thick, with the oversized pushers and the exposed gasket, and no interest whatsoever in being discreet.

The 26400 and 26405 generation uses a modular chronograph built on AP's automatic base calibre. It is worth knowing that in 2022 AP introduced a new generation of Offshore chronograph using an integrated in-house flyback calibre, which is a genuinely different and more sophisticated movement. That newer generation carries a substantially higher price. Whether the difference matters to you is a real question with a legitimate answer either way — the modular movement is proven, reliable, and has served the reference for a long time.

26405CE.OO.A002CA.01 is the full black ceramic execution: case, bezel, pushers and crown all in ceramic. It is one of the most impressive objects Audemars Piguet has produced, and it is worth understanding that machining and finishing a Royal Oak case in ceramic is an extraordinarily difficult manufacturing exercise — the material is far harder to work than steel and the Royal Oak's alternating brushed and polished surfaces have to be executed on it anyway.

26400SO.OO.A055CA.01 pairs a steel case with ceramic bezel, pushers and crown. It is the more wearable of the two, lighter, and less expensive — and the mixed materials are a deliberate design decision rather than a compromise.

Diver or Chronograph

What to check before buying

1. Case geometry above everything. The Royal Oak case is defined by the alternating brushed top surfaces and polished bevels, and by the sharpness of the boundary between them. Polishing destroys this and the damage is permanent and highly visible to anyone who knows the reference. Ask directly whether the case has ever been refinished, and inspect the bevels running down the case sides at an angle. See overpolishing.
2. The eight bezel screws. They should be evenly seated and consistently oriented. On the Offshore they are hexagonal; check for tool marks around them, which indicate someone without the correct tool has been in there.
3. Bracelet stretch. Hold it horizontally and observe the droop. AP bracelets are expensive and their replacement cost is a serious number.
4. Rubber and strap condition. On strapped models check the flex point for hardening. Original AP straps and deployant clasps are costly.
5. Ceramic edges on the 26405. Every corner, under strong light. Ceramic chips cannot be repaired — the component is replaced.
6. Service history. Ask when, by whom, and whether the case was refinished during it. AP service traditionally includes cosmetic refinishing unless declined, so a serviced watch has frequently been polished.

An honest word on value

Offshores do not behave like steel Royal Oaks on the secondary market. They were produced in greater numbers, across many more variants, and they do not carry the same allocation-driven premium. That is precisely why they are interesting: you can buy a genuinely serious Audemars Piguet, in the condition you want, today, at a number derived from actual transactions rather than from scarcity theatre.

For a buyer who wants the watch rather than the queue, that is not a downside. It is the entire opportunity.

Specifications vary across production runs within a reference family. Confirm the calibre, dimensions and materials on the individual watch rather than from the reference number alone.