@Horton - this discussion came up with regards to boat insurance itself, with a friend of mine who was a claims adjuster for many years. I questioned him about the exclusion for "illegal acts". What he told me was that was "easy reader" policy language and that if the insurance company were to deny coverage based on it, that it had better be a serious legal infraction like reckless endangerment or they would be setting themselves up for a bad faith lawsuit. The way he explained it was that for the most part, being drunk is still covered.
The big problem is that in any kind of accident, alcohol makes you guilty by association.
Last I knew, it was specifically illegal here in Illinois to waterski, wakeboard, etc. if you were legally over the limit. Never heard of it being enforced. But if there is no law specifically banning alcohol completely, I can't see how an insurance company can deny a basic medical claim in good faith. Then again I'm no lawyer and civil laws may vary state to state.
Common sense is dead in this country and quite frankly that is why I choose my guests carefully. One of my "friends" sneaked marijuana on board my boat about three years ago. He was the type who invited himself and didn't know an anchor from a paddle. We are no longer friends.