The short answer
A replica Omega Speedmaster Apollo 13 stands or falls on details you can see at arm's length: subdial position, the step in the dial, the print on the bezel, and the caseback. Nail those and the watch reads as a Moonwatch from across a table. Miss them and the whole thing looks wrong, even to someone who has never handled the real one.
What the real watch is
The Apollo 13 connection is the reason these Speedmasters exist. In April 1970 an oxygen tank ruptured on the service module, and the crew used their Speedmasters to time a 14 second midcourse correction burn by hand. Omega received NASA's Silver Snoopy Award later that year. The brand has marked the anniversary several times since, and the Silver Snoopy Award pieces plus the Apollo 13 anniversary editions are the models most often copied.
What to check first
- Subdial layout: 30 minute totalizer at 3, 12 hour counter at 6, running seconds at 9. On a genuine Moonwatch these sit close to the center, not pushed out to the edge.
- Dial finish: many references have a step, a raised ring around the minute track. Flat, shiny dials are the usual giveaway.
- Bezel insert: aluminum or ceramic with the tachymeter scale. The old "dot over 90" detail belongs to vintage references only, so match the bezel to whatever reference the watch claims to be.
- Crystal: hesalite on the classic references has a soft dome and a faint edge. Sapphire sits flatter and catches light differently.
- Caseback: engraving depth, the seahorse medallion, and the mission text. Crisp relief is expensive to fake.
- Bracelet: three link with the right taper, end links flush to the case, and a clasp that shuts without rattle.
The caseback is where replicas slip
The 50th anniversary Silver Snoopy Award piece has an animated caseback, where Snoopy orbits in a command module while an Earth disc turns. No replica reproduces that. If a seller promises full animation, expect a static engraving. On the Apollo 13 anniversary models the caseback carries the mission patch and text, so check that the relief is even and the lettering is not slopped with paint.
Movement reality check
Real Speedmaster Professionals are hand wound. If you can see a rotor through the back, the movement is not what the listing says. Most replicas run a copy of the Lemania based 1861 or a Seagull ST19 chronograph, and both can run well. The test is the pushers: start, stop and reset should each give a firm click, and the chronograph seconds hand should snap back to zero without wobble. Winding feel matters too. A gritty or slack crown shows up within a week of daily wear.
Where to spend your attention
I would take a copy with a clean dial and an honest caseback over one with a fancy box and a sloppy bezel. Lume is the other thing. Charge the watch under a lamp for thirty seconds, then look at it in a dark room. The plots should glow evenly, and patchy lume on the hands is common at the low end.
Questions worth asking before you buy
- Which reference is this copying, and does the bezel match that reference?
- Hesalite or sapphire, and does it match the original for that reference?
- Is the caseback static or animated?
- What movement is inside, and is it hand wound?
- Can you send daylight photos of the dial and an angled shot of the caseback?
One last note on sizing. The Moonwatch wears smaller than 42mm suggests, because the bezel eats much of the width and the lugs curve down. On a small wrist a correct copy still looks right. If it looks like a dinner plate, the case proportions are off.