Bump to Art.

There's really nothing you can wear or have to make a crash landing in a Cessna survivable. As noted from this post about the crash in Alaska that killed the passenger and seriously injured the pilot.

While I agree with Art completely, I wouldn't try to wear too much, especially if you were traversing water. All those clothes would weigh you down in the event of a splashdown.

So I guess just dress comfortably and appropriately for the terrain you're going over and pray you survive the initial crash.