Omega Seamaster Diver 300M references that begin with 210 are the current-generation dive watches introduced in 2018, most of them 42 mm steel models running the Master Chronometer calibre 8800. The digits after 210 identify the case material, size, movement, and dial version, so the full number is what tells you exactly which watch you are looking at.
What the 210 reference numbers identify
Omega reference numbers are built in blocks rather than as a single code. The 210 prefix points to the Seamaster Diver 300M family. The following blocks cover the case and metal, the case diameter, the movement family, and the dial and bezel variation. A number such as 210.30.42.20.01.001 therefore describes a steel, 42 mm Seamaster Diver 300M with a specific dial configuration.
Because the digits change with each dial, bracelet, and metal combination, two watches can look completely different and still share the same 210 opening. Always match the full number on the caseback, the warranty card, and the paperwork.
Key specifications of the 210 generation
- Case: stainless steel in 42 mm, with 43.5 mm versions also in the family
- Water resistance: 300 m, rated for saturation diving
- Movement: Co-Axial Master Chronometer calibre 8800, METAS certified
- Dial: ceramic with laser-engraved wave pattern
- Crystal: domed sapphire front and sapphire display caseback
- Signature details: helium escape valve at 10 o'clock, ceramic bezel with a dive scale
- Magnetic resistance: rated to 15,000 gauss
How to read an Omega reference number
The number is a description, not a serial. Reading it in blocks lets you confirm a listing without opening the case:
- First block: the collection and model family
- Second block: case material and finish
- Third block: case diameter
- Fourth block: movement type
- Final blocks: dial, bezel, and bracelet variant
What to check before buying
The Seamaster Diver 300M is one of the most copied watch designs in the world, so verification matters more than price. Buy from an authorized dealer or a seller with a documented service history, and confirm the reference matches across the caseback, the movement, and the card.
- Compare the engraved reference against the number on the warranty card
- Ask for the METAS Master Chronometer certificate where available
- Check that the wave dial, bezel insert, and crown markings are crisp and correctly aligned
- Have an independent watchmaker open the case before you pay a private seller
A Seamaster Diver 300M reference that starts with 210 is a modern, well-documented dive watch with a clear spec sheet. Confirming the full number is the quickest way to know exactly what you are buying.