Short answer
Start at the caseback, not the dial. A genuine 26470O has a sapphire display back, and through it you see AP calibre 3126/3840: striped bridges, mirror-polished bevels, black-polished screw heads, and a rotor with crisp engraving. Almost every fake in this reference puts a decorated Asian chronograph under there, and the finish looks flat. Next, measure the case. The real one is 42 mm wide with a thick mid-case, and fakes miss the profile in one direction or the other. Then look at the dial texture. The Mega Tapisserie squares should have real depth and sharp walls. A printed or soft-molded grid is the giveaway on cheap copies.
The reference in plain terms
The 26470 is the Royal Oak Offshore chronograph that replaced the 26170 generation. It has a 42 mm case, subdials at 12, 6, and 9, a date window at 3, and the octagonal bezel held by eight hex screws. The letter suffix tells you the metal: ST for steel, OR for pink gold, IO for titanium. The "O" in a listing is shorthand that drops the second letter, so a watch sold as 26470O is one of those three metals. Dials came in blue, black, silver, and a few boutique-only colors, on rubber straps or alligator with a pin buckle.
Case and bezel checks
Run a finger around the bezel screws. Genuine hex heads sit flush in their seats with deep sockets and a real chamfer on each edge. Fakes often use stamped heads with a shallow socket, or heads that stand proud of the bezel. Look at all eight together: if they sit at different heights, that is a problem.
Then check the case flanks. The Offshore has a stepped profile with a brushed top surface and polished chamfers that run unbroken from lug to lug. On fakes the chamfer fades out near the lugs, or the brushing runs the wrong direction. Crown guards should be crisp and symmetrical with a clean gap around the crown. The crown should thread on smooth and stop clean once seated.
Dial and hands
- Mega Tapisserie grid: deep, sharp squares with a matte finish inside the cells and slightly polished walls. Soft edges or a glossy flat pattern means a fake dial.
- Applied AP monogram at 12: thin, set flush, clean edges. Fakes run thick and look glued on.
- Hands: broad, with even lume fill that stops short of the polished edges. Sloppy fill or a bent tip is a red flag.
- Date at 3: narrow font, straight aperture edges. Replica date wheels are often too wide or printed on a cheap disc.
- Subdial rings and hands: the 12 o'clock counter, the 6 o'clock hour counter, and the 9 o'clock running seconds should sit at the same level with no gap under the rings.
Movement and caseback
Flip it over. The rotor engraving should be crisp and deep, the perlage or Cotes de Geneve even, and the screw heads black-polished. If the rotor text looks laser-etched and gray, or the bridges are uniformly brushed with no bevels, walk away.
Check the caseback engraving too: reference number, case number, and model text should cut clean with sharp edges. On gold references, look at the lug edges and the caseback rim for plating wear. Solid gold does not show a different color under the surface. Pusher feel matters as well. A genuine chrono starts, stops, and resets with a short, crisp click. On fakes the reset feels mushy, or the chrono hand snaps back past zero and stays there.
Strap, buckle, and weight
The rubber strap on a real Offshore has a dense, matte texture with clean molded edges where it meets the lugs. Fakes use a softer compound that feels slick and smells like plastic. The pin buckle engraving should be deep, not faint laser etching. Weight is a rough guide: steel heads feel solid but not leaden, titanium feels light, and gold feels noticeably heavy in the hand. If a seller calls a watch gold and it feels like steel on the wrist, that is your answer.
What good replicas get right, and what they never will
Top-tier replicas get the case silhouette, the Tapisserie pattern, and the overall look right in photos and at arm's length. What they get wrong is the movement. No replica delivers a 3126/3840 with the same architecture, so the pusher feel and chrono reset differ, and a watchmaker spots it in seconds. If you are buying a replica knowingly, judge it on case, dial, and strap, then accept the movement as the trade-off. If you are buying what you believe is a genuine watch, the movement is your best evidence. Also treat water resistance as unknown on any counterfeit. Gaskets and caseback sealing are an afterthought, so keep it away from pools and showers.
Paying checklist
- Ask for a straight-on caseback photo that shows the movement, not a stock image.
- Measure case width and thickness, or ask for calipers in the photo.
- Count bezel screws and check that all eight sit flush and level.
- Compare dial texture to reference photos of the exact reference and dial color.
- Confirm the reference suffix matches the metal being sold.
- Check chrono start, stop, and reset before money changes hands.
- Compare the asking price to recent sold listings for the same metal and dial.