The Short Answer
A replica Speedmaster 311 is a copy of the Omega Moonwatch Professional family, the hand-wound chronograph sold under reference numbers that start with 311. Before you compare finish or movement, check three hard numbers: case diameter at 42 mm, lug width at 20 mm, and the crystal type for the version you want. When those three match the genuine reference, the rest of the watch deserves a close look. When any of them are off, stop there and save your money.
Before You Start
- The exact reference number you intend to buy, written down
- A digital caliper or a steel ruler with millimeter marks
- A 10x loupe
- Daylight or a bright, angled lamp
- A soft cloth and a small screwdriver for bracelet sizing
How to Check a Replica Speedmaster 311
- Measure the case across the widest point, excluding the crown and pushers. A 311 reference reads 42 mm. Anything near 39 mm or 44 mm is a different watch wearing the same listing photos.
- Measure the distance between the lugs. It should read 20 mm. Then measure lug tip to lug tip and expect roughly 48 mm.
- Count the subdials. You want three: running seconds at 9 o'clock, a 30-minute counter at 3, and a 12-hour counter at 6. Pushers sit at 2 and 4, with the crown at 3.
- Rotate the bezel and read the scale. The tachy scale should be crisp, evenly spaced, and include the raised dot above the 90 marker found on modern Moonwatch bezels.
- Inspect the crystal under the loupe. A hesalite version has a domed acrylic with a faint molding seam and a soft edge at the rim. A sapphire version is flat, hard, and almost invisible at an angle.
- Flip the watch over and read the caseback. Check the seahorse engraving, the ring of text, and the depth of the stamping. Shallow, blurry engraving is the fastest tell on a cheap copy.
- Wind the crown about 30 turns, then start the chronograph and let it run for ten minutes. Reset the pusher and watch the hands snap back to 12 without creeping.
- Set the watch dial up and time it over 24 hours against a phone clock. A decent replica should stay within roughly 10 to 15 seconds per day.
- Check the bracelet. End links should sit flush against the case with no gap, and the clasp should close with a firm click.
Specs Worth Matching
Case size drives everything else, so treat 42 mm as the anchor. Thickness on a genuine 311 sits near 14 mm, and a copy that measures 16 mm or more will wear like a brick. The dial should carry the Speedmaster name above the center and the tachymeter print on the outer ring. Lume plots on the hour markers should glow evenly after a few seconds under a lamp; patchy glow points to a low-grade dial.
Red Flags
- Listings that show only studio photos and never a straight-on dial shot
- Subdials that sit too close to the center or crowd the date window
- Painted markers instead of applied metal markers
- A caseback with glued-on text rather than stamped or engraved text
- Seller claims of "genuine Omega" paired with a price under a few hundred dollars
Wear and Care
Treat the watch as you would any mechanical chronograph. Keep it away from strong magnets, meaning laptop speakers and tablet covers. Wind it at the same time each morning so the mainspring stays in a healthy range. Have the gaskets checked before you wear it near water, since replica seals are rarely tested at the factory. A quick rinse with a soft cloth after wear keeps the caseback threads clean and the bracelet from picking up grit.