This guide is intended for the novice gear buyer, although it has information pertinent to anyone purchasing SCUBA equipment.  While you can get a great deal on dive gear on Ebay, you can also easily buy something that cannot be serviced or is unsafe.  Before bidding do a little homework on the piece of equipment that you intend to buy.  I see alot of regulators and BCDs on here that are too old to be serviced (or if they can be serviced the parts are no longer in production and cost $$$$).  It is always a good idea to talk to the repair tech at your Local Dive Shop(LDS) before you bid.  They will know what can and cannot be serviced.  Also, after you recieve any SCUBA related item, take it to a qualified tech and get it checked out, the $ that it costs is worth your life!  Generally if the regulator is made of metal, it is old.  Most of the newer regs, with the exception of some titanium models, are made from plastic or a composite material.  Most of the metal regulators were manufactured were made in the 60's to 80's and parts are just no longer availible.  You should also know that brands like  Healthways, SeaPro, or AMF Voit Swimaster can be hard to get parts for because the companies no longer exist or don't make scuba gear anymore and Pro Sub can be down right impossible.  Try to avoid brand names that you are unfamilliar with as these are usually inferior.  Also if it is not a brand you would usually see in any of your local dive shops, avoid it.  Some brands are not made to withstand the rigors of some environments.  A brand or model that will perform fine in the warm waters of Florida might not work so well in the cold waters of British Columbia!  Your LDS doesn't sell them for a reason!  "New" regulators purchased over the internet can also cause problems because many manufactuers do not allow internet sales of their equipment and will not honor factory warranties.  Be cautious of companies that offer their own warranty as often times they will replace the product with one of a lower value rather than replace the item.  Many manufactuers today will not allow their products to be sold for less than a certain amount by authorized dealers.   Purchasing "new" equipment from someone that is not an authorized dealer can cause trouble further down the road, again the manufactuers may not honor warranties or provide service parts as these are usually grey market (factory seconds not intended for retail sale).  When buying used use a little caution, do some internet research or ask your LDS.  They are there to help, and if they wont, send me a message and I will try to awnser your questions for you.  Buying items such as lights, knives, fins, or anything else that does not have to do with life support underwater is usually OK, you probably won't end up too badly hurt if your knife rusts or your light floods (you should have at least one backup light if you are night diving anyway) but if you buy a bad regulator that decides to free flow at 100 fsw, you will probably not be so lucky!  Diving is as safe as you make it, your life is not worth saving a few dollars!

Good Luck and Safe Diving!

Howard Cunningham

PADI OWSI #193865