A counterfeit Audemars Piguet Royal Oak Offshore reference 25721 fails on four points before anything else: caseback engraving, date window shape, pusher construction, and case thickness. The real 25721 is a 42 mm steel chronograph released in 1993 and nicknamed "The Beast" for its bulk and its 15 mm profile. That shape is expensive to reproduce at scale, so copies cut corners where a loupe and a caliper find them in under a minute.

What the 25721 Really Is

The reference 25721 sits at the start of the Offshore line. It carries the octagonal bezel with eight visible screws, the Mega Tapisserie dial with its raised grid, two pushers at 2 and 4 o'clock, a screw-down crown, and an integrated case that tapers into a rubber strap or steel bracelet. The black-on-steel and blue-dial versions are the ones most often faked, because the blue and the grid texture photograph well and get resold fast.

How to Check a Suspected 25721

  1. Measure the case across the bezel at 3 and 9 o'clock. The real watch is 42 mm. Copies land at 40, 41, or a swollen 44 mm, and the bezel screws sit too far from the edge.
  2. Measure the case thickness from the caseback to the crystal. The genuine profile runs about 15 mm. A thin copy shows up here first.
  3. Put a loupe on the date window. On the real dial the aperture edges are cut clean and the numerals are sharp with even weight. Copy printing looks flat and slightly fuzzy at 10x.
  4. Study the dial grid. Mega Tapisserie squares have sloped, raised sides that catch light from different angles. A stamped copy keeps the pattern but loses the relief, so the grid goes flat under a phone light.
  5. Turn the pushers. Genuine screw-down pushers thread smoothly and lock down with a light seal. Replicas feel gritty, stop early, or do not thread at all.
  6. Turn the crown. Count the rotations until it seats. Six to eight smooth turns is normal on the original. Two loose turns points to a stripped copy tube.
  7. Read the caseback engraving with a loupe. Look at the depth of the cut, the font weight, and the spacing between the reference number and the serial. Laser etching on a copy is shallow and the letters crowd together.
  8. Inspect the clasp or tang buckle for the AP hallmark and check the rubber strap for a molded part number. Copies use generic hardware with no markings.
  9. Match the serial on the caseback to the number on any paperwork the seller shows. Mismatched numbers mean the papers belong to another watch.

What to Do If You Are Offered One

  1. Ask for the original purchase receipt and the service history in writing.
  2. Request photos of the caseback at 10x magnification before you travel to see the watch.
  3. Have an independent watchmaker with AP experience open the case and confirm the movement and the reference.
  4. Walk away if the seller refuses an inspection or pushes for a cash sale on the spot.

Legal Reality in the United States

Selling or trafficking counterfeit watches is a federal crime, and shipments get seized at the border and destroyed. Buying a copy for personal wear is not the same offense, but you have no legal recourse when the watch arrives broken, and you cannot resell it without exposing yourself to a trafficking charge. A counterfeit 25721 also carries no service support, so a failed movement becomes a paperweight. If the price on a 25721 looks too low for the reference, the watch is the reason.