If you are interested in home made floatbags, which it doesn't appear
you are....below is a link to instructions for making them from PVC. Cost is
less than $10.00US for all parts. Labor will be about 60 minutes , less as
you get better at it.

The main advantage of making your own is... "If you can make them,
you can repair them". Another advantage to making them yourself is
custom shaping / sizing them to fit your boats.

Tom