The short answer

A fake Planet Ocean Ultra Deep 6000m is a watch that prints "6000m / 20000ft" on the dial and has none of the engineering behind it. The genuine Omega is a 45.5 mm diver rated to 6,000 m, ISO 6425 certified, and built around a case, crystal, and seal system that went to the bottom of the Mariana Trench to prove itself. A replica copies the silhouette. It cannot copy the pressure testing, and that is where every tell comes from.

What you are comparing it to

Omega's Ultra Deep line arrived in 2022, three years after prototypes rode Victor Vescovo's submersible to the deepest point in the ocean. Retail sits around $11,500 to $13,000 depending on the version. Two variants matter here: Grade 5 titanium with manta lugs, where the strap screws into the case with no spring bars, and O-MEGASTEEL, a stainless alloy Omega developed for this watch. Both run the same no-date Master Chronometer movement, Calibre 8912, good for roughly 60 hours and certified by METAS.

Know that baseline and the fakes get easy to read.

Tells that show up again and again

A date window

The Ultra Deep has no date. If a listing shows a date at 3 o'clock on an "Ultra Deep," the dial was not modeled on the real thing.

Regular lugs on a titanium version

Manta lugs are the giveaway. On the titanium Ultra Deep the strap mounts with screws into the case, so there are no spring bars and no lug holes. A titanium-look replica with drilled lugs and spring bars is a different watch wearing the name.

The crystal

The real one carries a domed sapphire that is genuinely thick, because a 6,000 m rating demands it. Fakes use thin sapphire or mineral glass with weak anti-reflective coating. Tilt it under a lamp. A real Ultra Deep stays readable from every angle with almost no glare washout.

Caseback and card

The caseback carries the depth rating, and the titanium model gets a stamped medallion. Genuine watches ship with a METAS Master Chronometer card whose number matches the movement. Replicas often have a generic card with no matching number, or nothing at all.

Weight and thickness

Hold it. The Ultra Deep is a 45.5 mm case with a lot of sapphire and titanium or steel around it. Fakes tend to feel light for their size, and the bezel action is loose with visible backplay. The real bezel clicks firmly and stops clean.

Price

Anything in the low hundreds is a replica. No exceptions, no "factory overrun" story.

Why the 6,000 m label means nothing on a fake

ISO 6425, the divers' watch standard, requires a watch rated to 6,000 m to be tested at 125 percent of that depth. That is 7,500 m of pressure on the case and crystal, not a brochure claim. A replica with a thin crystal, ordinary gaskets, and a decorative screw-down caseback is a 50 to 100 m watch on a good day. You are paying for a dial, not a diver.

The part people skip

Counterfeits have no service path. Omega will not touch one, independent watchmakers usually will not either, and there is no parts supply when a gasket or crown tube fails. Resale is effectively zero. In the US, importing counterfeit goods can get the shipment seized by Customs and Border Protection, and trafficking in them is a federal offense under 18 U.S.C. 2320. If what you want is a 6,000 m diver you can actually dive, the fake is the expensive option.