Coast Guard also says you must have one type I,II,III,or V onboard for every member ... If it doesn't fall in those categories it wouldn't pass a check. Unlikely you'd get checked during a regatta but possible.
http://uscgboating.org/safety/fedreqs/equ_pfd.htm


"I said, now, I said ,pay attention boy!"

The cure for anything is salt water - sweat, tears, or the sea
Isak Dinesen
If a man is to be obsessed by something.... I suppose a boat is as good as anything... perhaps a bit better than most.
E. B. White