The Audemars Piguet Royal Oak Offshore reference 26401 is a 44 mm chronograph. Replicas sell for $200 to $1,200. Genuine examples trade from about $30,000 to $70,000. The fastest check is the movement. No replica carries an AP calibre 3126/3840. Ask for a photo of the rotor and bridges, or open the caseback.
What reference 26401 means
AP made the 26401 as a 44 mm Offshore chronograph. Variants differ by case metal. AP puts a metal code in the reference. RO is 18k rose gold. IO is titanium. PO is platinum. SR mixes steel and rose gold. A seller who calls a steel watch a 26401RO has the reference wrong.
Shared traits: black ceramic bezel, rubber-coated crown and pushers, sapphire crystal, 100 m water resistance. AP lists calibre 3126/3840 for this line. Reported figures are 365 parts, 21,600 vibrations per hour, about 50 hours of power reserve, and a gold rotor. Specifications differ by variant. Confirm with AP before you buy.
Movement tells
Replica 26401 watches use copies of the Miyota 9015, the Seagull ST19, or the ETA 7750 family, or a cheaper quartz module. Signs of a copy:
- Rotor spins with no resistance and no winding feel.
- Bridge stripes are laser-etched, not cut. Edges look flat under a loupe.
- Power reserve under 40 hours.
- Subdial hands jump instead of sweeping.
Case and bezel tells
- Bezel screws. Genuine Offshore screws pass through the case and thread into nuts on the back. Slot angles are random. Replicas show eight slots at one angle, or screws that are glued in and decorative.
- Weight. A rose gold case weighs about twice a steel case of the same size. A plated fake feels light for its bulk.
- Crown and pushers. Genuine rubber overmolds sit flush. Copies show mold seams and gaps at the collar.
- Caseback. Genuine engraving has sharp edges and even depth. Copies show shallow, rounded lettering and a soft AP logo.
Dial and date checks
The dial texture is the Mega Tapisserie grid. Squares are raised and cut at one angle. Printing is crisp at 10x magnification. Look at the date window at 3 o'clock. AP uses a narrow date font. Replicas use a wide font, and the date wheel sits low or high in the window. Check the subdial rings and the AP logo at 12 o'clock for uneven spacing.
Numbers that do not match
- Price. A $900 listing for a 26401 is not genuine.
- Serial. AP can verify a serial and reference pair at a boutique or service center.
- Papers. Genuine sets include a numbered card and a certificate that match the caseback.
Legal status in the US
US law bans trafficking in counterfeit goods under 18 U.S.C. 2320. Importing a counterfeit watch breaks 19 U.S.C. 1526, and CBP can seize the shipment. Penalties include fines and prison time.
What to ask a seller
Request a movement photo, a caseback photo, and a weight in grams. Compare the serial with AP. Pay for an inspection at an AP service center or a watchmaker with an AP parts account. If the seller blocks any of those steps, stop.