Aluminum frame with what appears marine grade plywood. I bought it several years ago and then had knee surgery. I’ve only used it 4-6 times on the daily in Moab and A,B section of green.

If you are going to load it down, I would suggest larger diameter tubes to keep you out of the water a little better. And could use some d rings welded on for larger water.

It was great to “get my feet wet” and play around on but I don’t use it enough. I welded up the trailer with new axles and CDC plywood top. Which I was going to apply a texture to for non slip in the middle. When wet, it’s slippery. It’s been store inflated and out of the sun. Holds air. I don’t see any issues mechanically.