Rough approximation of boatable flow range from low to high levels: do not rely on this information to make safety decisions.
Number Four is the most challenging rapid on the the run. It's a bit of a double-drop. Aat lower flows, it's easy to pause between the drops. At higher flows, they merge together. It's a pretty chill paddle out of the gorge from here, with some impressive accumulations of large wood as you approach Patrick Creek.