Donna, ZoE has doggles. She has the goggle looking kind, not the sunglass looking kind, but I could bring them over for Lola to try, so you'd see how they'd fit & stay on. ZoE would only wear hers while riding in my son's Jeep Wrangler, with the top off. Any other time, and she'll paw at them until she gets them off.
As for a sided float...how about getting a little kids swimming pool...the kind that has the blow up rings as sides. I know they will float (as I used to put ice in one & then set adult beverages in it, & float it in the pool for easy access
). Your hubby could always cut a piece of foam sheeting to fit the bottom if you were worried about nails going through the vinyl bottom.
Here's what I'm thinking off: