There are two things that I learned whilst listening to Legal Aspects Lecture at the many, many ITCs that I staffed:
- There has never been a lawsuit based on selling air that did not relate to the quality of the air.
- You open yourself to greater liability when you check for certification than when you just sell a product.
That's a great point and one that is consistent with the legal issues and interpretations we encounter in the program compliance and evaluation we do.
If the shop just fills the tank, they are leaving both the assumption of the end use and the responsibility to determine the person's qualifications for that use, on the customer not the shop. Once the shop asks for a cert and then sells the gas, they have in effect made a judgment that the person is qualified.
For example: My first cert was received in 1985. Some of the people in that class no doubt still have their cert but may not have been in the water in the last 25 years. Does a cert mean they are qualified to dive, and by extension to get their tank filled? Obviously not, but if we both walked into a shop and we both pull out our 1985 certs, the shop owner cant tell the difference without asking questions about currency, competence, etc. That question and answer process however opens the owner to even more liability as he would have to make a judgment of the diver's qualification to dive based on his or her answers and that judgment will be questioned in the event the diver dies or is injured while diving - and in that case the outcome already suggests the shop owner's judgment was seriously flawed. What is worse is that it serves no real purpose as the answers may not be honest.
In the end it's better not to ask at the fill station/shop level. There may be criticism that the shop owner is not following a self imposed scuba industry standard, but the shop owner only needs to point out the wider range of uses and customers for the air products he sells, plus the above analysis of the pointless nature of carding to defeat that attack on two different levels.
I see some aspects of charter boat diving as being a little different. For example with a live aboard tech charter, if some moron offs himself on dive one, day 1 the trip is basically over so as a customer I appreciate the captain doing some basic screening of c-cards and experience levels. Also, unlike an LDS, the captain and crew can observe the diver and not allow them in the water if they do not demonstrate the ability, equipment or planning to do the dive safely, or the can prohibit the diver from making additional divers if they are unsafe in the water.
That is also just a general extension of the captain's overall liability when he determines the conditions on-site are suitable for diving.