Short answer
"512" is not an Omega reference number and not an Omega caliber. It shows up in listing titles for replica Seamaster 300M Diver watches. Sellers use it as a batch code or a listing code. One code can cover several watches, and codes get reused. Read "512" as a seller label, not a model name.
What the genuine watch is
Omega builds the Seamaster Diver 300M under references such as 210.30.42.20.03.001. Published specs:
- 42 mm stainless steel case, 300 m water resistance
- Ceramic dial with laser-engraved wave pattern, date at 6 o'clock
- Ceramic bezel with enamel dive scale
- Calibre 8800 Co-Axial Master Chronometer, 55-hour power reserve
- METAS Master Chronometer certification, anti-magnetic to 15,000 gauss
- Helium escape valve at 10 o'clock, screw-down crown
These numbers come from Omega. A replica ad that repeats all of them is making a claim, not reporting a measurement.
Where the number 512 appears
The code appears in three places: marketplace item IDs, seller batch names, and photo folder names. None of them map to Omega's numbering system. Omega references follow a nine-part pattern, as in 210.30.42.20.03.001. A three-digit code does not fit that pattern.
If a listing says "512" and gives no Omega reference, the listing gives no model identity. Ask which reference the seller is copying. If the answer changes between messages, the code carries no information.
Movement named in replica listings
Genuine Seamaster 300M watches run the 8800 or the 8900. Replica listings name movements such as "A2824", "2824 clone", "Miyota 9015", or "8800 clone". These are different movements. An 8800 clone is a decorative plate over a third-party automatic. Fields that differ from the genuine caliber: beat rate, power reserve, magnetic resistance, and service parts.
Water resistance claims
Replica cases ship with gaskets of unknown material. A listing that states 300 m does not mean the case passed a pressure test. No public test data exists for these cases. The genuine 300 m rating comes from Omega's own testing.
Legal status in the United States
Counterfeit watches are illegal to import. U.S. Customs and Border Protection seizes shipments that carry counterfeit marks. Trafficking in counterfeit goods falls under 18 U.S.C. 2320, which carries fines and prison terms. A buyer can lose the money paid when a shipment is seized and the seller offers no refund.
Checks on any listing
- Reference number. A listing with real detail names the Omega reference it copies.
- Movement name. "Clone" and "decorated" mean a third-party movement.
- Case size. 42 mm is the current Diver 300M. Older models differ.
- Serial engraving. Genuine serials sit on the lug and are laser-etched, not stamped deep.
- Bracelet code. Genuine clasps carry a code and a date stamp.
- Return terms. Sellers with no refund terms leave the buyer holding the risk.
Bottom line
"512" identifies a seller listing, not a watch. Judge any listing by the Omega reference it names, the movement it states, and the import risk.