The best assurance that you can gain is: Stay off boats!.. Like anything else you can ensure that common sense is the most predominant factor. You are in more danger in a car than a boat, as long as the skipper knows his stuff. Wearing life jackets, having on board survival tools like: flares, locator unit, fire extinguisher, food & water, maps etc are as important as your ability to enjoy boating without worrying about safety as the expense of your enjoyment.
Come fishing with us.. We chase Marco Sharks (they often jump into your boat when hooked)