I knew Larry. I know he had boots on but right next to him in the water was Dawn Riley's dad who was much older and I'm sure not in Larry's shape and he survived. All the others survived and I would have predicted the opposite. Very tragic.
i know of a case about 25-30 yrs ago where a crewmember in a double-handed race in early June survived north of the buoy position for an hour without a PFD. Even your link shows that is possible (page 36). Not something I would like to experience and normally wear a Mustang Suit if the water...
Southern buoy on Lake Michigan (45007;http://www.ndbc.noaa.gov/view_climplot.php?station=45007&meas=st)indicates an average water temp in June of around 52 degs. Looking at survival charts for that temp, you would have over an hour. However, it would be the longest hour of your life...