Sorry about your friends. What were the circumstances? What mistakes did they make? What kind of boat? What were the conditions?
Look, I've been boating all my life and I'm in the marine industry. I put over 200 engine hours on my personal boat a year not to mention all the time I spend on other boats. I own a couple thousand dollars worth of life jackets. Those in my field consider me an expert. As such I can state the following:
You're wrong.