Short answer
Omega did not release a watch named the Seamaster 300 70th Anniversary. The Seamaster line started in 1948. The 70th year fell in 2018, and Omega marked it with the Seamaster 1948 Limited Edition, a 38 mm steel watch on a leather strap. The Seamaster 300 dive watch came in 1957, so its 70th year is 2027. Sellers use the 70th anniversary phrase for two different references. Ask for the reference number before you pay.
The two watches behind the search term
Most listings that use this keyword show one of two models.
- Seamaster 1948 Limited Edition, 2018. 38 mm steel case. Two dial versions: small seconds and central seconds. Calibres 8804 and 8806. Master Chronometer certified. 1,948 pieces per version.
- Seamaster 300 Summer Blue, 2023. Built for the 75th year of the line. 41 mm steel case. Calibre 8912. 300 m water resistance. Blue gradient dial. Blue ceramic bezel with enamel markings.
A listing with "70th anniversary" in the title and a 41 mm dive watch in the photos is the Summer Blue model. The year in the title is wrong.
Genuine specs to compare against
Seamaster 1948 Limited Edition
Case: 38 mm, stainless steel, polished bezel. Crystal: domed sapphire. Caseback: solid, engraved. Strap: leather. Movement: Omega 8804 or 8806, co-axial, Master Chronometer. Production: 1,948 pieces per dial version. The caseback is closed, so no movement is visible.
Seamaster 300 Summer Blue
Case: 41 mm, stainless steel. Bezel: blue ceramic with blue enamel. Crystal: domed sapphire. Dial: blue gradient, applied indices. Water resistance: 300 m. Movement: Omega 8912, Master Chronometer. Bracelet: steel. The dial runs from light blue at the top to dark blue at the bottom.
How replica versions are built
Replica Seamaster watches use third-party movements. Common choices are the Seagull ST2130, the Miyota 9015, and the Hangzhou 6300. Some builders use a decorated movement that copies the look of a co-axial rotor. None of these are Omega calibres. Service and spare parts come from the movement maker, not from Omega.
Case steel is the second difference. Most copies use 316L stainless steel. Weight and finish change from factory to factory, so two copies of one model can feel different on the wrist.
Dial details decide the look. Genuine dials use applied indices and pad-printed text. Better grades of copies use the same method. Cheaper grades print the indices. The 1948 uses beige lume. The Summer Blue uses blue lume.
Bezel inserts come in two types: ceramic and aluminum. The genuine Seamaster 300 uses ceramic. A copy with an aluminum insert will not match the color under light.
Checks before you buy
- Reference number. The 1948 LE starts with 511.13. The Summer Blue Seamaster 300 starts with 234.30. Compare the number with the Omega catalog entry for that model.
- Case size. 38 mm for the 1948, 41 mm for the Summer Blue. Measure the case, not the bezel.
- Weight. Ask the seller for a scale photo. Compare it with a known sample of the same model.
- Movement name. If the seller claims an Omega 8912 or 8806, the claim is false. Omega does not sell loose movements.
- Caseback. The 1948 has a solid engraved back. A copy with a display back does not match the genuine watch.
- Bezel action. Genuine dive bezels use 120 clicks. Count the clicks by hand.
- Lume. Charge the dial with a phone light for 30 seconds. Check the color and the glow time.
- Water. No replica factory pressure-tests to 300 m. Do not swim or shower with a replica.
Claims to ignore
- "Same factory as Omega." Omega does not contract third parties to build Seamaster watches for outside sale.
- "Swiss made movement." Most builds in this price band use Japanese or Chinese movements.
- "Limited to 1,948 pieces." That number belongs to the genuine 2018 release. Copies have no serial limit.
- "1:1." No public standard defines the term.
Price and legal status
Replica prices come from the seller. There is no public index for these models, and no factory publishes output numbers. Treat any "Swiss made" or "1:1" line as marketing text.
In the United States, trafficking in counterfeit goods is a federal crime under 18 U.S.C. § 2320. A first offense carries up to 10 years in prison. Customs officers can seize shipments. A replica has no Omega warranty and cannot be serviced by Omega.