Short answer
A fake Patek Philippe 7118 blue dial is a counterfeit copy of the Nautilus 7118/1A-010, a 35.2 mm steel self-winding watch. Copies sell for USD 200 to USD 2,000. The genuine reference trades in the tens of thousands. The gap shows in the dial texture, the date disc, the bracelet edges, the clasp engraving, and the movement. No copy runs a Patek Philippe caliber 324 S C.
What the genuine 7118/1A-010 is
The 7118 is the mid-size Nautilus. Patek Philippe lists these points:
- Case: 35.2 mm, stainless steel, sapphire on the front and the back, water resistance 60 m.
- Movement: caliber 324 S C, self-winding, 28,800 vph (4 Hz), 45-hour power reserve.
- Dial: blue with an embossed horizontal pattern, white gold applied numerals, luminous coating, date at 3 o'clock.
- Bracelet: steel, integrated into the case, fold-over clasp with the Calatrava cross.
Patek lists other 7118 versions with a diamond-set bezel and in rose gold. Each uses the same dial pattern, so the checks below apply to all of them.
Dial checks
- Pattern: the genuine grooves are cut into the plate and lacquered. The blue shifts from dark navy to mid-blue as light moves across it. Copies read flat, purple, or gray.
- Date window: the genuine aperture sits at 3 o'clock with a bevel and a date disc matched to the dial. Copies show a plain white disc, a thick font, or a date that sits off center.
- Printing: "PATEK PHILIPPE" and "GENEVE" carry even serifs. Copies show smeared or thick letters. Look at the "P" and the "G".
- Numerals: genuine markers are solid white gold with a flat polish. Copies are plated brass. Plating pits within months and shows green or pink at the edges.
- Hands: the seconds hand reaches the minute track. Copies cut it short by half a millimeter or more.
- Lume: genuine lume sits inside the applied numerals. Copies paint lume on top of the marker.
Case, caseback, and movement
The genuine case flanks carry a satin brush and a polished bevel that meet along one crisp line. Copies round that edge. The caseback sapphire shows the movement: Cotes de Geneve stripes, perlage on the plates, a 21K gold rotor with the Calatrava cross, and jewels set in gold chatons. Most copies hide a decorated Seiko NH35, a Miyota 8215, or an unnamed 2824 clone. A genuine 324 S C uses a Gyromax balance; copies use a flat balance with a screw regulator. Some copies run quartz, which shows in a seconds hand that jumps 1 second at a time.
Serial numbers matter. Genuine watches carry a case number and a movement number, and the two match the Certificate of Origin. Copies stamp a number that repeats across batches.
Bracelet and clasp
The Nautilus bracelet tapers from the case and the links sit tight with no visible gap. Copies show gaps of 0.5 mm and sharp corners on the outer links. Open the clasp: the genuine part has a deep laser-cut Calatrava cross, a firm two-stage fold, and a safety catch. Copies etch a shallow cross or leave a blank plate. Screw bars in the genuine bracelet turn with steady resistance; copies cross-thread.
Price and paperwork
Patek Philippe lists the steel 7118/1A-010 above USD 40,000, and secondary market prices sit higher. An offer under USD 5,000 for a steel blue Nautilus is a copy. Genuine sales include the Certificate of Origin, a wooden box, a leather wallet, and a booklet. An authorized Patek Philippe retailer or service center can confirm the case and movement numbers against factory records. Ask for that check in writing before money changes hands.
If you own a suspect 7118
- Read the case and movement numbers with a 10x loupe and compare them with any papers.
- Have a watchmaker open the case. A copy shows a movement holder ring, a plastic spacer, or a movement with no Patek stamp.
- Send the watch to an authorized service center for inspection and a written finding.
- Keep the seller listing and messages. Trafficking in counterfeit goods violates 18 U.S.C. 2320 in the United States.