Any of you tow a TT and carry a boat above truck bed/cab?

My 12 foot aluminum rides atop our van on a Thule brand rack. I camped next to a guy who had the rack system you describe. He had a fairly large aluminum boat on a trailer that rode above his truck bed & cab. I watched him load & unload. Seemed fairly simple. He had no complaints. Loked a tad top heavy IMHO. I think the brand was "Eddie Loader" BTW We fish three nicely out of our car top aluminum using an electric trolling motor