I wasn't questioning anyone's credentials & apologize if anyone took it that way. I was just more or less curious & concerned about the possible implictions of such a thing occurring. I personally have my instructor examine & repair my equipment, including my tanks. I have seen her credentials & trust her. I gladly pay the fees she charges to perform these services for my safety & the safety of anyone who must handle my equipment. I knew going into diving, that having my own equipment, I would have to keep up the maintenance on it & that it wouldn't be cheap (I believe firmly in the "you get what you pay for" saying). I am hoping in the future to eventually be able to get the proper training to help out my LDS with the equipment maintenance duties, but that's a way off & I have other things to get done first. Please don't take my questions as an insult, take it as someone who wants to learn & to do the right things to keep my gear in safe & tip top shape.