The short answer
A fake Aquatimer Chrono is only worth your money if you accept three things up front. It is not an IWC. IWC will never service it. And nobody will pay you anything close to your purchase price for it later. Inside those limits, the gap between a $120 quartz knockoff and a $400+ "first copy" comes down to two things: the movement and the finishing on the case, bezel, and bracelet.
Here is what actually separates the tiers, and what I check before spending.
Know the watch being copied
The steel Aquatimer Chronograph that most replicas imitate is a 44mm diver rated to 300m, with an internal rotating dive bezel and a chronograph built on the Valjoux 7750 architecture (IWC calls its version caliber 79320). That matters for one reason. A 7750-based chrono has a specific feel when you press the pushers and a specific behavior when the rotor spins. A quartz copy cannot fake either one.
The three tiers you will run into
- Quartz knockoff. Cheap, light, wrong subdial layout, stamped caseback. Skip it unless you want a costume piece.
- Entry automatic. Usually a low-grade 7750 clone or a rebadged Asian chrono movement. Runs, but the pushers feel mushy and the chrono second hand can stutter.
- First copy. Higher-grade 7750 clone, properly finished case, working internal bezel, correct dial printing. This is the tier most buyers mean when they use the term.
Price tracks tier closely. If someone offers a "first copy" at a price that matches the entry tier, you are being sold the entry tier.
What I check in person or in photos
- Subdial layout. Compare against the exact reference you are copying. Running seconds and chrono counters should sit where the real dial puts them. Mismatched layout is the fastest tell.
- Internal bezel action. It should rotate with detents, not spin loose and not grind. The two crowns should each do one job only.
- Pusher feel. Firm start, crisp stop, clean reset to zero. A chrono hand that resets to 1 or 2 seconds past 12 is a warning.
- Case finishing. Look at the transition between brushed and polished surfaces. Soft, rounded edges mean the case was machined fast.
- Dial printing. Text should be sharp under a loupe, not fuzzy or doubled. Applied markers should sit flat.
- Lume. Charge it under a lamp for 30 seconds and check in a dark room. Weak, uneven glow is common on low tiers.
- Weight and balance. A 44mm steel diver has heft. If it feels hollow, the case is thin-walled.
- Bracelet end links. They should sit tight against the case with no rattle or gaps.
Things to be honest with yourself about
Water resistance on a replica is a guess. Seals are not tested to 300m, and I would not swim with one. Chrono movements in this price band need service eventually, and a local watchmaker may or may not take the job. There is no warranty behind the watch and no parts network.
Then there is the legal side. Selling counterfeit goods is illegal in the United States, and US Customs can seize infringing imports. Buying one for personal wear is a different question than selling one, but the shipment risk is real and refunds are hard to enforce across borders.
Care once you own it
Keep it out of salt water and hot showers. Do not run the chrono constantly, since that wears the module faster. Wind it gently and let it rest if it is not a daily wear. Store it away from magnets, which includes laptop speakers and tablet cases.
Buy the tier you can afford, from a seller with clear photos of the actual unit, and treat it as a fun object rather than an investment. That framing keeps the whole thing simple.