Fake or counterfeit watches are the bane of the modern collector, particularly when buying online. One way to protect yourself is only to use known reputable dealers, however, that means you miss out on some of the bargains, and also a broader range of watches online.
Buying an expensive used watch online can be a nail biting exercise and you need to do all you can to protect yourself. If you buy on ebay use PayPal, and credit your PayPal account with a Credit Card, as opposed to a bank debit card. This will give you a little more protection.
Always ask for credentials / provinence for the watch you are purchasing, be that original packaging, manuals, receipts, serial numbers etc and if possible check with a dealer that the serials are genuine and not stolen.
Speak to the seller about the watch. Many people selling fake watches have little idea about the original versions of the watches they are selling, asking lots of questions may give more insight as to whether the person is genuine.
On top of that, do as much resesarch as you can, and if possible collect the watch in person.
There are some great resources online which can be used to help you identify fake watches which we are compiling below:
Resources for Identifying Fake Omega Watches
Fake and Genuine Omega Seamaster 300 Compared (illustrated)
CronoCentrics Guide to Fake Watches (illustrated)
An Ebay Guide to Identifying a Fake Omega Seamaster Pro (illustrated)
An Ebay Guide so Spotting a Fake Omega Seamaster 300 (illustrated)
Resources for Identifying Fake Rolex Watches
Quality Time have some useful free information on spotting fake Rolex Watches, though they also sell an ebook on the subject which you will have to pay for.
Some Useful Tips on Spotting Fake Rolex Watches from the Horologist.
Basic tips for spotting fake rolex Sub Mariners, Daytonas and Sea Dwellers from product dose.
Ebay Guide on Fake Rolex Watches (credited to the Horologist)
Resources for Identifying Fake Breitling Navitimers
An interesting post on Breitling Source showing some pretty convincing fake Navitimers.
Another page from Breitling Source comparing dials of some older looking fake Breitlings, not very convincing.
General Resources for Identifying Fake Watches
Ehow have a number of articles on spotting various fake watches though the information is a little generic.
Article on fake Omega Speedmaster, Breitling Navitimers and Rolex Sea Dwellers, these are quite convincing models, worth a read!