Tigerman:
No, I would not dive with a diver that was not certified as my buddy. Not because that diver neccesarilly is a bad diver, but because I, as the one that IS certified, would be held responsible if something went wrong...
Can you reference a legal precedent to support that?
Portions of the industry use cards to decide who they will or won't sell certain products or services to. If you are a dive shop or instructor, your insurance policy will require you to adhere to agency standards.
I am under no contractual obligation to do any such thing as far as I know. My limited knowledge of tort law (is that the right term?) is that I am responsible for acting as a resonably prudent person in any given situation. If my failure to do so results in damages to another, I can be held liable.
Being on a dive with an uncertified diver or a diver who is doing something that they aren't certified to do is unlikely to be the direct cause of any damages to them...unless maybe if I somehow push them into diving.
Cards don't mean much to me. the minimum requirements to become certified are, in my opinion, not sufficient to qualify a diver to dive under any conditions. Before I dive with an unfamiliar buddy a skill evaluation is going to be used to decide what kind of dive, if any, we are going to do. When I was an instructor I came across many CERTIFIED divers who I wold NOT take on any dive at all without remediation in pool like conditions.
One time, I had a husband and wife team who had just completed their AOW cert come to me for a nitrox course. They didn't even get a quarter of the way through the skill evaluation before I decided that I couldn't take them on any kind of a dive. They couldn't even descend without flopping around all over the place. We spent half the day just going over the most basic skills in very shallow water right near the shore before we could do any nitrox dives.
When I was an instructor and when I owned a dive shop, I was obligated to look at c-cards. I don't look at them any more.