Short answer
"210" is the reference prefix for the Omega Seamaster Diver 300M family. Reference 210.30.42.20.03.001 is a 42 mm steel watch with a blue ceramic dial and a steel bracelet. Omega fits it with calibre 8800, a Master Chronometer movement, and rates the case to 300 m. Watches sold under the phrase "replica Omega Seamaster Diver 300 210" are counterfeits. They have no Omega warranty, no METAS certificate, and no serial number in the Swatch Group records. US law bars their import and their sale.
Genuine reference facts
- Case: 42 mm, stainless steel, 300 m water resistance, helium escape valve at 10 o'clock.
- Dial: blue ceramic with a laser-engraved wave pattern and applied indexes. The 2018 generation replaced the flat dial with this ceramic wave dial.
- Bezel: blue ceramic with a white enamel diving scale.
- Movement: Omega calibre 8800, co-axial escapement, 35 jewels, 55 hour power reserve, silicon balance spring, 15,000 gauss magnetic resistance.
- Certification: METAS Master Chronometer, eight tests, average daily rate of 0 to +5 seconds.
What the reference blocks mean
Omega does not publish a full key for every block of its reference numbers. Dealer sources agree on a few parts. 210 marks the Seamaster Diver 300M line. 42 marks the 42 mm case. 03 marks the blue dial. The remaining blocks cover case metal and bracelet type. Confirm a single reference with an Omega boutique or an authorized dealer before you buy.
How copies differ
Counterfeit cases use lower grades of steel or plated brass. Plating wears at the lugs and the crown. The bezel insert is printed or painted, so the scale fades with use. Water resistance is not tested, and a listing that says "300 m" has no test data behind it. Movements inside copies are generic automatic or quartz calibres. A genuine 8800 has a co-axial escapement and a decorated rotor. Common faults on copies include a date font that does not match, a misaligned bezel triangle, uneven brushing on the bracelet, and a crown that does not seat flush.
Law in the United States
Two statutes matter. 15 U.S.C. 1114 covers civil infringement. 18 U.S.C. 2320 covers trafficking in counterfeit goods and sets a prison term up to 10 years for a first offense. 19 U.S.C. 1526 and 15 U.S.C. 1124 let Customs and Border Protection seize and destroy imports that carry a counterfeit mark. Statutory damages under 15 U.S.C. 1117(c) run from $1,000 to $200,000 per counterfeit mark, and up to $2,000,000 if the use is willful. Personal possession is not a federal crime in most cases. Import, sale, and resale are.
Genuine pricing
Omega lists the steel blue-dial Diver 300M in the low $6,000 range. Prices change with each annual update, so check the current figure with an authorized dealer. Used examples trade below retail. Ask for the three cards: international warranty, pictogram, and Master Chronometer certificate. Match the serial on the cards to the case and to the movement.
Verification steps
- Match the serial on the caseback to the warranty card.
- Ask a watchmaker to open the case and check the escapement and the movement finish.
- Compare the weight and the bracelet feel against a genuine example at a boutique.
- Run a pressure test at a service center. A copy will not hold 300 m.