Below Predator, the short box canyon opens up and there's a large eddy on river left to collect yourself before Waterfall Rapid. Essentially, Waterfall is a broken five-foot ledge. At lower levels, small boats can dash far left to sneak around the worst of the hydraulic. At higher flows beware of the river driving into the right wall below the ledge, hence this rapid's alternate name: Wall Slammer. This rapid might earn a class IV-/IV rating at higher flows.