Actually not wearing a life jacket kills more. You don't have to be a drunk to be stupid on the water, just ask any PWC rental rider.
Being a responsible operator of a watercraft is just not stressed enough today. It's just too easy to get your hands on a 60mph-70mph water rocket without any real training.
Pretty scary, if you think about it.
Every stat I read states acohol is responsible for more boating accidents / fatalities than any other cause. Where's Boatcop to back me up on this one?