Well, in the uk at present, you can buy a jetski at any age, stick it in the water, knock back as much booze as you like, and then race it up and down 5 knot boat lanes. It's not just about diving, it's about other boat operators, damage to other peoples vessels, local wildlife, of which there have recently been basking sharks and dolphins injured as a result of juvenile motor boat operators harrassing them, and riding over them by accident or otherwise. I myself do not enjoy being over legislated, but I also find that a swim out to a local dive site i use involves frantic SMB waving on the hotter and sunnier days, at one point a pleasure boat even came in extra close so the tourists on board could "see the scuba divers" How were they to be sure that there really were just two of us, and no-one just below the surface.
As for "I don't want to go down and spend a day in a class, wait in line and pay money for a useless piece of paper that will not slow down a jet skier."
You paid money for your diving certification I assume, and you attended courses to ensure you were not a danger to yourself or others. Without your useless diving card, you will find it hard to get air fills and join reputable dive boats. So why do we allow someone to take to the water in something far more dangerous, and make themselves a liability to the public and rescue crews who have to come out and retrieve them when they start sinking, without at least getting someone to sit and run them through the correct way to pass another vessel, rights of way and exclusion zones, (And that an SMB indicates that there may really be someone under the water that they could kill).
Surely something to ensure someone has some common sense before allowing them to take control of a boat isn't a bad thing.
