Slip N Sliding Away

I bought a two-laned slip n slide for the kids to start enjoying their summer water fun. Even though they said the water was freezing and our ground isn't all that smooth, they enjoyed it for about an hour. I kept hearing a lot of "OWs" and I felt bad for them and told them to stop if they were getting hurt. But, of course they weren't going to do that--I guess the fun of it outweighed the bruises they might get on their knees or other body parts. I wonder if I bought them one of those body-sized floating-raft-type-thingies and they used it as a body board if that would help? I have hope that our new house's lawns are a lot smoother and I know they definitely are more padded with grass, so the slip n slide will work better there. Oh, to be a kid again.