Although I agree with much of your sentiment about answering "no" on the medical form, it doesn't offer any protection to the LDS/charter operator from a suit from your heirs (at least in the US). On your (untimely demise) they can sue for most any reason they dream up. I believe it would cover them from a suit from you if you had an undisclosed "limitation" that injured you didn't kill you outright. Probably not a high-runner but it doesn't cost much.
I shoulda worded that differently. Offers protection from any "
legitimate" lawsuit. And yes, it does absolve them of liability. It's called "fraud" (on my part). Neither you nor your estate can sue if your standing in court is based on fraud (fruit of the poison tree). I know that anyone can sue over anything (that's why I stopped practicing law in 2000), but a BS lawsuit will be quashed on summary judgement (hopefully). Let's say I have chronic bronchitis with scarred lungs and the dive shop/charter boat owner doesn't give me a form to sign, and doesn't ask about my medical issues, and I go diving and die under pressure at 100 feet due to a lung problem that was compounded by my bronchitis issue. They were negligent. That's a fact. My estate will sue and they will win. Because, as a matter of law, you can disclaim negligence, but in none of Obamas 57 states can you disclaim
gross negligence. Undertaking a life-support sport without inquiring about a participants health is gross negligence.
Now if I have chronic bronchitis with scarred lungs and they have me fill out the form, and I lie, and I die, then they have exercised due diligence. They have no liability. They had no way of determining, except by my answer, if I had a problematic medical condition. I've met no dive instructors that were also licensed physicians, although there probably are some.
Now if I fill out the form truthfully, and go pay the Dr. $75 bucks to "ok" me, once he puts his signature on the form, then once again, the dive shop has exercised due diligence. They have no liability.
So it is, in fact, all about who gets sued, not actual diver safety. I betcha if I got turned down by one doc, I could just go find me another Doc and another Doc until I found a slob who jut signed the form. Let's not forget the DEA fiasco in California when medical marijuana came out. Date Line did an undercover report. All they did was pay the Doc the $250 fee and the doc issued a medical marijuana card all without a physical and even without asking any questions. The office visit was like 7 minutes long. Date Line sent several people in with hidden cameras and several dozen "clinics" were shut down as a result.
My dad is a truck driver. The state makes him take a DOT physical every year and the doc has to fill out a four-page form and my dad send it in to the state before his CDL is renewed. This year he took the form to his V.A. doc and the doc just signed it and handed it back to him.