Several of us here are paddlers. Your profile says nothing as far as where you are so I can't comment on any float trips.
www. paddling.net is a good forum to explore.
As far as boats go, I have a composite boat for lakes, slow rivers, touring/camping type stuff and a couple of poly boats for shallow water.
Both of the poly boats are Dagger Blackwater 10.5's (the old and new versions) and handle rocks and scrapes in stride. I'd buy them again in a heartbeat. What sounds like a serious scrape leaves little noticeable damage on the hulls.

I'm around Dallas and paddle year round.