Trace, you’re a bright guy, but you're asking the wrong question.
Let me give some background to who I am, for those of you that don't know. Trace and I know each other personally for over a decade. I've been a 100 Ton Boat Captain, running charters in the Keys, and today I am currently a technical dive instructor for cave and ccr. I also own one of the largest Property, Casualty and Life Insurance agencies in the country. I have licenses in 20+ states and I'm a claims adjuster in almost two dozen states. I'm also a pilot with several friends running jump planes for skydivers. I think it's safe to say that I know a little bit about liability.
So, back to Trace's wrong question. Your question shouldn't be why do dive professionals need insurance when Skydive instructors don't. Your question should be, how many of those skydiving accidents involved litigation and what was the result of that litigation.
Because I PROMISE you that a liability waiver is the next closest thing to worthless. 90% of people out there don't realize that they're worthless, and that's the majority of protection that they carry is that people think, "Man, sure wish I could sue, but dammit I signed that liability waiver". These waivers have been beat in court more times than they haven't been. Years ago, I heard Witherspoon tell a guy at DEMA that if his student didn't sign that waiver, Witherspoon wouldn't defend the instructor in litigation. It doesn't really work that way. But it was a nice threat. There's a contract filed with the state that says how and when you defend someone. You don't get to arbitrarily decide if/when you protect your insured. Read your contract.
But I digress. Dude, you don't have to have insurance. Create your own agency. Make your own rules. You're a likable guy. I'm pretty sure you'd be successful. But this country sues for the dumbest stuff on the planet. Do you know what I'm worth today? NO WAY IN HELL am I putting it all at risk to save $600/yr.
2 years ago a client of mine ordered pizza from Dominoes. The kid delivering the pizza knocked on the door and then took one step up the 2 stairs to enter the doorway. He slipped, grabbed the railing and cut his hand on the railing. An ambulance was called and the kid received one stitch to close the wound. We paid the kid through Medical Payments to Others. We covered his lost day of work, the ambulance ride, stitches, even the dropped pizza. The kid sued my client for $75k AND WON. Now, here's the funny part. The kid was at work. Workers Comp covered all of this as well, everything except the dropped pizza. The kid was made whole, twice. That's the bs country we live in. And you're going to try and teach cave diving, but save $600 on insurance? If so, scratch that first sentence where I said you were a bright guy. I take that back.
