If you are shopping for a fake Patek Philippe Nautilus 6790, the key fact is that no replica factory is known for that reference. The number does not appear in Patek Philippe's published Nautilus lineup, so most listings that use it are rebadged 5711 or 5712 builds with a different number in the title to catch search traffic. The strongest option on the market is a top-tier 5711 based clone with a purpose-built copy of the 324 S C movement. Judge any listing on five criteria: the movement inside the case, the case and integrated bracelet, the dial printing and date wheel, the seller's willingness to send QC photos, and whether the purchase is legal where you live.

Why the 6790 reference is a warning sign

A reference that does not match the watch in the photos means you are comparing apples to apples only by accident. A listing titled 6790 may show a 5711 style case with a 5712 style dial, or a case size that does not match the engraving on the back. Before you send money, ask three questions.

  • What caliber is in the watch, and is it a dedicated clone caliber or a decorated third-party movement?
  • What reference is engraved on the case back, and can the seller photograph it?
  • What are the case diameter, thickness, and bracelet width as measured with calipers?

A seller who answers with photos and measurements is worth more of your time than one who answers with adjectives.

Criterion 1: The movement

The movement decides how the watch feels on the wrist and how it survives a service. Two build types dominate the market.

Purpose-built clone caliber

  • Pros: correct hand stack, correct date change behavior, rotor and bridges shaped like the original architecture, smoother winding feel.
  • Cons: higher cost, fewer independent watchmakers will touch it, spare parts can be hard to source.

Decorated third-party movement (Miyota or Seiko based)

  • Pros: proven reliability, widely serviceable, lower entry cost.
  • Cons: wrong case thickness in some builds, decorative plates that do not match the original layout, and a rotor engraving that reads shallow under light.

Ask for a timegrapher photo that shows rate, amplitude, and beat error. A reading near zero seconds per day, amplitude above 250 degrees, and low beat error is a healthy sign at any tier.

Criterion 2: Case, bezel, and bracelet

The Nautilus case is a rounded octagon with a flat bezel and a satin brushed top surface. On a well-made example the border between brushed and polished surfaces is crisp, and the bezel sits flush with the case. Check these details.

  • Bracelet taper: links should narrow toward the clasp in even steps rather than all at once.
  • End links: should sit tight against the case with no visible gap and no rattle when you flex the watch.
  • Crown: should sit centered between the crown guards and screw down with firm resistance.
  • Finishing: brushing lines should run in one direction on a panel, not swirl across it.

Lower tiers show rounded bevels, uneven brushing, and a bracelet that feels light for its size. Ask for a photo of the watch on a scale if the seller claims a specific weight.

Criterion 3: Dial, hands, and date

Dial work is where cheap builds fall apart. Under a macro photo, the brand text should be level, the minute track should be unbroken, and the applied markers should sit straight. On date models the number should sit centered in the window with no tilt, and the font should match the reference the seller claims to copy. Lume application should be even across every marker, with no pooling at the edges. Ask for a daylight wrist shot and a macro of the dial, not studio renders or stock images lifted from another listing.

Criterion 4: Seller screening and QC photos

The watch matters less than the person selling it, because you have no warranty to fall back on.

Specialist sellers

  • Pros: they know which builds have known flaws, they will send a specific QC set, and they can usually source a replacement bracelet or clasp.
  • Cons: higher prices, longer waits, and some refuse refunds after QC approval.

Open marketplaces

  • Pros: fast shipping and buyer protection platforms.
  • Cons: mixed stock, stock photos instead of real QC images, and no accountability for a movement that arrives dead.

Request photos of the dial, the case back with the engraving, the crown side, the clasp code, and the timegrapher screen, all with your name or order number in frame.

Criterion 5: Legal risk and ownership reality in the US

Counterfeit watches are illegal to import and to sell in the United States. Customs can seize and destroy a shipment, and there is no recourse through the seller when that happens. Beyond the law, a replica arrives with no manufacturer warranty, no parts support from Patek Philippe, and a water resistance claim you should not trust near water. Never buy one to resell as genuine, and do not take one to a boutique for service.

Which tier fits your use case

Entry tier

Best for someone who wants the look for occasional evening wear and accepts visible tells at close range. Keep it away from water and treat it as costume.

Mid tier

Best value for regular wear. Bracelet feel and dial printing improve, and the case profile gets closer to the original. Still not something a normal watchmaker will service cheaply.

Top tier

Best for buyers who compare details against reference photos and want the closest match. Budget for a service on arrival and keep the watch dry regardless of what the listing claims.

If what you want is the real thing, the honest path is a pre-owned genuine 5711 or 5712 with documentation and an inspection by a qualified watchmaker before you pay.