archer1960
Contributor
I see them as being rooted in liability. If a dive operator is willing to take the liability of letting someone dive without a cert card, dive outside their cert limits, fill tanks that they don't show a cert for, that's up to them. Some are very loosy goosy with that decision, some make it based on who they know, some decide based on how much money they will lose if they don't serve you as a diver, and then others stick to the letter of the law to cover their own butts. This is why cert card "requirements" vary so widely from country to country, state to state, and even dive shop to dive shop.
I don't own a dive operation but if I did, I would probably be very strict about needing to see a card. It wouldn't be to be a jerk or to stop people from diving but there is one enormous benefit, one added bonus, and one under-appreciated benefit that I see on the business side of being strict:
1) First and foremost, it protects me from liability. When an open water diver has a fatal heart attack underwater and happens to be at 70ft when it happens, his family will try to sue me for everything I'm worth. My career would risk being over and I would risk bankruptcy. It would be up to the judge to decide but I can protect myself against their lawyers by not allowing him to dive beyond what he has proven to me that he is certified to do.
2) Less important than that, it allows me to sell more courses. "Hey man, you're an open water diver and we have some awesome sites below 60ft. I can help get you there by doing and advanced course for you. Oh, you want to go deeper still? How about my decompression class!" Some people take this way too far and I disagree with their tactics but done right, this mentality can increase business.
3) As a customer, I look for dive operators that have a reputation for following standards. Being asked and seeing others asked for cards is one of those ways that the operator is actively and visibly following standards making me more likely to recommend them to friends.
There are a lot of shortcomings to the certification card system, there is no doubt about it. However, in a world where we can fabricate dive logs, lie about experience, and embellish how good we are, the certification card is a way that dive operators can protect themselves.
At the end of the day, it's their prerogative to either take the liability by letting you dive or to protect themselves by not allowing you outside of what you can prove your certified for. After all, in Florida all you need to legally dive is a dive flag. You can have all of your own gear and dive all you want but the certification card issue only comes up when you go to dive with a shop or have your tanks filled.
That makes sense for diving with the shop, but I don't quite understand why they would require a C-card to fill tanks. Compressed air is used for lots of things beside SCUBA diving...