For about $25, Parafunalia in Gilford has these bright yellow swimmer's belts that are sturdier than a home made foam noodle belt, which pretty much perform the same way.
Once in the water, is not so easy to get into a pfd, while it is fairly easy to get into a swimmers belt with just one click of the plastic snap, or one bowline knot with the noodle belt.
Probably, if the swimmer's belt were a color like gray or khaki they would sell better than bright yellow. The belts encourage people to go swimming which is very doable now with the 80-degree water temps.
https://www.weather.gov.btv/60daytemp shows the Lake Champlain water temp at 78-degree, probably the warmest for the summer, on Tuesday July 30, day of surprise storm/big wave drowning.