How to read the references, date the cases, and tell each Offshore generation apart before you buy.
The Royal Oak Offshore arrived in 1993 as reference 25721ST, a deliberately oversized reworking of Gerald Genta's Royal Oak. Emmanuel Gueit pushed the case to 42mm, added a thick exposed rubber gasket between bezel and case, fitted screwed pushers and crown guards, and earned the nickname "The Beast." Three decades later the Offshore is its own family, spanning steel, gold, titanium and ceramic across several sizes. This guide breaks down the references you are most likely to encounter and how to identify each.
AP references follow a fixed pattern: model number, case-metal code, a code for the strap or bracelet attachment, the strap/bracelet reference, then a dial code. Take 25940SK.OO.D002CA.01.A. The 25940 is the model, SK indicates steel, D002CA is the rubber strap reference, and the trailing digits identify the dial and variant. Learn the metal codes and most of the watch decodes itself: SK and ST are steel, OK is pink gold, IO is titanium, ZZ appears on certain ceramic-bezel lug configurations. A rose-gold example reads 25940OK, while a titanium piece reads with the IO code, as on the 26078IO.OO.D001VS.01.
This is the heart of the model. The first generation 25721 ran from 1993 into the early 2000s on a Jaeger-LeCoultre-based calibre 2126/2840. It was replaced by the "Rubberclad" 25940, introduced around 2005, which is the reference most often seen on the secondary market today. The 25940 keeps the 42mm case but adds rubber cladding to the bezel, pushers and crown, and ships on an integrated rubber strap with the D002CA reference. You will find it with the classic black "Méga Tapisserie" dial, an Arabic-numeral black dial as on the 25940SK.OO.D002CA.01.A, and in pink gold with a gray dial on leather, reference 25940OK.OO.D002CA.02. From 2006 AP fitted its in-house calibre 3126/3840, a meaningful upgrade over the earlier supplied movement.
In 2014 the line was redrawn as the 26470, a sharper 42mm case with a ceramic pushers-and-crown treatment on many variants and updated bracelet integration. From roughly 2018 onward the newest generation moved to the integrated in-house calibre 4401, found in references such as the 26420. When dating a 42mm chronograph, the movement is your anchor: supplied 2840, in-house 3126/3840, then the integrated 4401 mark three distinct eras.
The Offshore also lives at 44mm. Titanium chronographs such as the 26078IO.OO.D001VS.01 sit in this group, pairing a lightweight case with the heft the design implies. The Royal Oak Offshore Diver, introduced in 2010 as the 15703, is a separate 42mm three-hand model with an inner rotating dive bezel and a screw-down crown at ten o'clock, later joined by a Diver chronograph at 42mm. Do not confuse the Diver's inner bezel and ten o'clock crown with the chronograph cases; they are different references entirely.
Not every Offshore is a brick. The 37mm steel chronograph, reference 26076SK.ZZ.D010CA.01, was offered with a white "Méga Tapisserie" dial and ceramic bezel, aimed at smaller wrists and at buyers who want the Offshore look in a more wearable diameter. These mid-size pieces use the same design language, scaled down, and are worth seeking out if 42mm and 44mm feel excessive on the wrist.
Match every code on the case back to the watch in front of you. The case material code must agree with the metal, the strap reference must match the fitted strap, and the dial should correspond to the final digits. Rubber straps and gaskets are wear items; cracked or hardened rubber is normal on older 25940 examples and is a service cost, not a deal-breaker. Check that pushers and crown screw down crisply, and confirm the movement matches the production era. Box, papers and an AP service record support both price and provenance. Polishing is less common on Offshores than on dressier watches, but verify that the bezel screws and case lines remain sharp.
Our current Offshore inventory runs seven pieces from roughly $21,000 to $44,000, which is representative of the broader used market for these references. Steel 25940 chronographs anchor the lower band, titanium and the 44mm cases sit in the middle, and pink-gold examples reach the top. Special and limited editions trade well above this range and are priced individually. For a first Offshore, a clean steel 25940 with in-house movement, original rubber strap and complete paperwork remains the most defensible buy: iconic proportions, a robust caliber, and a deep pool of comparables to value it against.
Live inventory for this model — updated continuously as pieces arrive and sell.
