Top pick: a genuine, authenticated Patek Philippe Aquanaut from a seller who puts the authentication in writing, because that is the only version of this watch that a service center will open. The four criteria used here to judge any Aquanaut, real or not, are movement and caseback, dial and hands, case and strap finishing, and paperwork tied to a serial number that can be verified.

Why This Reference Draws the Most Fakes

The Aquanaut arrived in 1997 as the ref. 5060A: a steel case, an embossed grid dial, and a composite strap made to match it. It was built as the looser, more wearable counterpart to the Nautilus, and that is exactly what makes it a target. The outline is simple, the dial pattern can be stamped onto a plate, and the strap hides the case gaps where cheap work usually shows.

Two references drive most of the interest: the 5167A, the 40 mm steel time and date model, and the 5168G, the larger white gold jumbo. A third, the 5164A Travel Time, gets copied less often because the extra pushers and the second time zone mechanism are hard to fake in a way that survives handling.

Criterion 1: Movement and Caseback

What a real one shows

  • Most modern references have a sapphire display back, so the movement is meant to be seen and judged.
  • Bridge and rotor finishing is done to the standard the brand publishes as the Patek Philippe Seal.
  • Rotor engraving sits deep and crisp, with edges that do not bleed into the surrounding metal.
  • A watchmaker can read the movement number and cross-check it against the case number.

Where fakes fall down

  • Rotor text that is laser etched and shallow rather than engraved.
  • Decorative perlage or Geneva stripes laid over cast, unfinished surfaces.
  • Blued screws that are painted steel, with the slot cut after the coloring.
  • A solid caseback where the reference should have a display back, or a display back with nothing worth showing behind it.

Use this test first: ask for a clear movement photograph and the movement number before any money moves. A seller who refuses is answering the question for you.

Criterion 2: Dial, Hands, and Date

What a real one shows

  • The grid is pressed into a metal blank, so the raised squares catch light differently as the wrist turns.
  • Applied numerals sit flush, with lume fill that stops at the edge of the aperture.
  • Hand bevels are polished and the seconds hand sweeps without hesitation.
  • The date window is cut clean, centered, and uses the wheel font the reference calls for.

Where fakes fall down

  • A printed grid that looks flat and never changes with the light.
  • Numerals glued slightly off axis, or a date that sits low in the window.
  • Lume that is lumpy under a loupe or that glows a different shade on the hands than on the dial.
  • Print that flakes at the edge of a marker after light handling.

This is the criterion most buyers can check alone, with a phone macro lens and a window. Compare what you see against published photographs of the exact reference, not the model in general.

Criterion 3: Case, Bezel, and Strap or Bracelet

What a real one shows

  • The rounded octagonal bezel carries brushed flats and polished bevels that meet on a defined line.
  • Lugs are cut so the strap or bracelet sits tight against the case with no light gap.
  • The composite strap flexes, keeps its shape, and matches the dial tone.
  • The clasp engraving is deep and the folding action is firm.

Where fakes fall down

  • Bezel edges that feel sharp enough to catch a fingernail.
  • Brushing that runs the wrong direction or stops short of the lug.
  • Strap material that smells strongly of rubber and stiffens within weeks.
  • Clasp text that is stamped thin, or a clasp that rattles when closed.

Handle one in person if you can. Photographs hide edge quality better than any other flaw on this list.

Criterion 4: Papers, Provenance, and Price

What a real one shows

  • A serial and movement number that a service center can confirm.
  • Service records, original receipts, or a dealer statement that names the watch.
  • A price that tracks the current secondary market for that reference.

Where fakes fall down

  • Certificate paper with the wrong weight and finish.
  • The same serial appearing across several listings.
  • A price far under the prevailing market, framed as a private sale or an urgent one.

There is a legal layer here too. In the United States, trafficking in counterfeit goods is a federal offense, and counterfeit watches are subject to seizure at the border. A fake also leaves you with a watch no authorized watchmaker will service.

Option 1: A Genuine Aquanaut on the Secondary Market

  • Pros: verifiable serial, serviceable movement, resale value, no legal exposure.
  • Cons: cost sits well above original retail for steel references, and stock is thin.

Best for the buyer who wants the actual watch and expects to keep it for years.

Option 2: An Integrated-Bracelet Steel Sports Watch

  • Pros: same silhouette language, full warranty, dealer service network, a fraction of the outlay.
  • Cons: it is not an Aquanaut, and no one who knows watches will think it is.

Best for someone who likes the shape and the casual steel look more than the name on the dial.

What to Avoid

  • Any listing that uses the word replica, mirror, or super clone as a selling point.
  • Sellers who will only communicate through encrypted chat apps.
  • Payment methods with no dispute process, such as gift cards or direct transfers.
  • Auctions ending in hours, which exist to stop you from doing the checks above.

Bottom Line

Run the four criteria in order. Movement and caseback first, because it is the hardest thing to fake. Dial and hands second, since you can check it yourself. Case and strap third, ideally in person. Paperwork and price last, because that is where a good copy gets sold as something it is not. If any one check fails, stop, no matter how good the other three look.