My boyfriend did it for the second year in a row, only they call it the Penquin Plunge in Jamestown, Rhode Island.
It looks like such fun with all the comradiary (sp?) and exuberance. It's a black tie affair, many of the members go in wearing a tux, or they strip down to their swim suits, but leave their bow ties on. My bf wore his uncles powder blue prom tux, circa 1973. It was too funny.
It's used as a fund raiser for the Special Olympics.
For a minute, while watching them, I thought "Wow, I want to do that". But then I remembered what a wimp I am about extremely cold temperatures.
All I can say is, good for you, you brave warrier!