Omega Seamaster Diver 300M 210.30.42.20.03.001

The case measures 42mm across and 13.6mm thick, with a 20mm lug width. Case material: Stainless steel. Case size alone is a poor guide to how a watch wears; lug-to-lug length and how the bracelet drops off the case matter more, which is why we suggest trying one on before you commit.

Automatic, Omega Cal. 8800, Co-Axial Master Chronometer. Power reserve is 55 hours. It beats at 25,200 vph. The movement uses 35 jewels.

It is rated to 300 meters, about 984 feet. That is a diving rating: it is built for scuba use, not just for getting wet. One caution that applies to every watch on this page: a water resistance figure describes a new watch with fresh gaskets. On a piece that is years past its last service, treat the rating as unknown until it has been pressure tested.

Omega produced this reference from 2018 to the present day. Production years matter when you are valuing one, because dial, bezel and bracelet details often changed inside a single reference run.

210 = Seamaster Diver 300M; 30.42 = steel 42mm; the final dial-code block changes by color (e.g. 03 = blue, 06 = grey). Reading the reference is the fastest way to confirm that a watch is what the seller says it is, before you get anywhere near the movement.

Diver 300M color-dial family (blue / grey / "Black-Black"). Collector nicknames are not official Omega names, but they are what people actually search for and what they are called across a showroom.

Yes. We buy this reference outright, and we lend against it if you would rather keep it. We are a family-owned San Diego buyer established in 2006, our appraisers are GIA-trained, and the appraisal is complimentary with no obligation to sell. You can bring it to our Gaslamp showroom at 907 Sixth Ave or start online. If you are looking to buy this reference instead, tell us and we will let you know when one comes in.