Answer first
Judge the movement and the case geometry before you judge the logo. A fake Speedmaster 311 that gets the 3-6-9 subdial spacing, the 42 mm case width and a hand-wound chronograph right will sit convincingly on the wrist. A copy that hides a modular automatic chronograph behind a dial with the wrong subdial positions never will, no matter how good the photos look. Ask the seller for a caseback photo, a straight-on dial shot and a short video of the chronograph running and resetting before money changes hands.
What the 311 reference family actually is
Reference numbers starting with 311 belong to Omega's modern Moonwatch Professional line. That family is defined by a 42 mm stainless case, a tachymeter bezel with a dot over ninety, a three register dial with running seconds at nine, and a hand-wound movement. Some 311 references use a hesalite crystal, others use sapphire, and later versions moved to a newer co-axial manual caliber. Knowing which base your chosen copy is meant to imitate tells you what the dial and caseback should look like.
What to look for
Movement type
The Moonwatch Professional is a manual wind chronograph. Any copy with a display back showing a rotor is imitating the wrong watch. A closed steel caseback with engraved seahorse or speedmaster text is the correct silhouette. If the seller cannot name the base movement inside, treat that as a no.
Dial and subdials
Subdial spacing is where most low grade copies fail. The three registers should sit close to the center and align at three, six and nine. A date window at three or six is wrong for a Moonwatch Professional, and pushers that look oversized or sit too far from the crown are another common flaw.
Case, bezel and crystal
Check lug shape, crown guards, and how the bezel meets the mid case. Printing on the bezel should be crisp rather than smeared. A domed hesalite style crystal and a flat sapphire version both exist, so match the crystal to the specific version you are buying.
Spec bands worth checking
- Case diameter: 39.7 mm to 42 mm depending on the version being copied
- Lug width: 19 mm to 20 mm
- Lug to lug: roughly 47 mm to 48 mm on the 42 mm case
- Thickness: about 12.5 mm to 14.5 mm
- Caseback: solid steel, engraved, no display window
- Water resistance claim: if it is stated at all, it should match the real rating for that version
Pitfalls to avoid
- Stock catalog photos instead of shots of the actual watch you will receive
- Sellers who cannot show the chronograph running in a video
- Listings that mix details from two different references, such as a sapphire crystal with a hesalite era dial
- No stated return window, or a policy that only covers damage in transit
- Payment methods with no buyer protection
- Any suggestion that the watch could be passed off as a genuine Omega to a future buyer, which is fraud in most jurisdictions
FAQ
Can a first copy Speedmaster 311 use a real Omega movement?
No. Copies use third party or generic chronograph calibers. Sellers claiming an in-house Omega caliber in a copy are misrepresenting the product.
Why is subdial spacing such a big deal?
Because it is the hardest thing to fake on a small budget. Automatic chronograph modules push the registers outward, which changes the whole look of the dial at a glance.
Does the 311 prefix cover every Moonwatch variant?
It covers the modern Moonwatch Professional family, but crystal type, bracelet and movement generation vary within it, so match the copy to one specific version rather than a blend.
What should I inspect on arrival?
Time the chronograph start, stop and reset, check the pusher feel, look for dust under the crystal, and confirm the caseback engraving matches the version you ordered.