They did in PORS and Vero Beach. They also have swim vests that you can check out with resort ID.
I saw all kinds of flotation divices at PORS, but when we got to Vero Beach they did not let my DD use her ring blow up. They said it had to have something that actually atached to her. They did have a number of things you could borrow from them. (and noddles too.)
Most do alow water wings. (BC and WL did.) I know Beach club doesn't allow anthing else. (like your own blow up tubes, you have to rent theirs.)