The Omega Seamaster 300 70th Anniversary uses a blue gradient Summer Blue dial, a ceramic bezel with enamel fill, and a Master Chronometer calibre 8912. Most copies match the silhouette and miss everything else. If you are buying, check four things in this order: the dial gradient, the bezel enamel, the caseback medallion, and the movement finish.
What the 70th Anniversary Seamaster 300 Is
Omega released the Seamaster 300 70th Anniversary in 2023 as part of a Summer Blue collection marking 70 years of the Seamaster line. The steel version carries a 41 mm case, a ceramic bezel with a blue enamel dive scale, and a dial that fades from a pale blue centre to a deep blue edge. The sapphire caseback shows a commemorative medallion, and the watch is certified as a Master Chronometer. Water resistance is rated to 300 m.
Before You Inspect
- A 10x loupe or a phone macro lens
- Calipers and a digital scale accurate to 0.1 g
- The official reference listing for the exact model you are viewing
- Daylight near a window, not overhead indoor light
How to Spot a Fake, Step by Step
- Read the dial from the centre out. On the real watch the blue shifts smoothly across the whole surface. Copies print one flat blue or show a hard band where the gradient was sprayed.
- Inspect the bezel insert. Genuine ceramic holds numerals and markers filled with blue enamel at an even depth. Fakes show painted fill, raised edges, or markers sitting off centre.
- Study the hands and lume. The genuine hands have crisp polished edges and lume that sits flush in the frame. Copies run thicker, and the lume tone often differs from the dial markers.
- Turn the watch over. The sapphire caseback carries the anniversary medallion. Copies use printed or shallow laser etching that flattens under a loupe.
- Measure the case across the bezel, crown excluded. A genuine steel case measures about 41 mm. Copies frequently run 0.3 to 1 mm wide or thick.
- Weigh the watch on the bracelet. Genuine steel lands in a tight range for the reference. Fake cases use lighter alloys and usually read low.
- Check the movement through the caseback. A calibre 8912 shows striped finishing on the rotor and bridges, a relief Omega logo, and engraved Master Chronometer text. Copies show plain rotors with printed lettering or a decorative plate over a third-party movement.
- Ask for the Master Chronometer card. Every certified watch ships with one and its test data is retrievable. A seller who cannot produce either is not selling a genuine piece.
- Match the reference number on the case to the number on the card and the catalogue listing. Any mismatch ends the conversation.
Details Most Copies Miss
- Bezel action: genuine clicks are firm and even with no back play. Copies feel loose or gritty.
- Crystal: the double-domed sapphire has an anti-reflective coating that shifts colour as you tilt the watch. Copies flare green or purple.
- Bracelet: brushed and polished links alternate with straight, sharp edges. Fakes show rounded edges and soft brushing.
- Crown: threads engage smoothly and the logo is cut clean, not stamped.
- Print: the dial text has consistent stroke weight. Copies thicken or thin the lettering.
Questions to Ask a Seller
- What is the full reference number, and does it match the card?
- Can you send the Master Chronometer test data for this watch?
- Are the bracelet and end links original to the reference?
- What is the return window if the watch fails an inspection?
Bottom Line
A steel Seamaster 300 70th Anniversary trades in a narrow price band on the secondary market. If a listing sits far below that band, the watch is not genuine, no matter how good the photos look. Bring the loupe, bring the scale, and ask for the card before money changes hands.