Years ago, I had 2 Float N Tote fly rod holders for my Wood River tube & loved 'em. Apparently, they are no longer made, but I am hoping to find a used one (or 2) in good shape. They were light, not bulky, & adjusted easily from vertical to horizontal facing forward or back. While I am not closed to the Scotty rod holder, I had used the Float N Totes & they met my wants/needs perfectly.
Hopefully, someone has one or two they'll sell.