Okay... I debated telling you about this... but...
I was watching one of those storm stories on the weather channel one day... and... they had these people who were in Ophelia (I think... some hurricane on the Atlantic). Anyway, they ended being saved because they latched onto a mattress. Mattress' apparently float. I didn't know that, but now I do. I hope you never need that info... but... if you do... you know.
I doubt I'll need to, thankfully. I'm about a mile and a half from Biscayne Bay, but they're not expecting surge there greater than 2 to 4 feet. The immediate area where my house is located is the highest ground in Cutler Ridge. When Katrina came through, she dumped 18 inches of rain here. All of Cutler Ridge had 2 feet of floodwater for several days, except for two or three blocks around my house.