The problem with kayak/ladder racks that are commercially available, is that they don't leave room for the tonneau cover. This kayak rack works using the existing stake pockets and as long as the tonneau cover doesn't cover them up you can freely open and close the tonneau cover AND carry your stuff in the rack.
It is all about getting there. Had to create a rack for two 10 foot kayaks on a Ford Ranger. Copied idea from other PVC racks. Have a fill tube on this one to weigh down the rack and a plug to drain the water when done.