The three of them aimed their throws without slowing down, and felt the boom as they whipped past their targets and circled back around. As predicted the visible damage was practically nothing, but they weren't firing, and one of the tanks was pushing against the side of another, its operator having slumped against the driving levers. After several seconds it reached the edge of the river and fell in, the angle it fell at, and the weight of the water rolling it along until it went right over the waterfall.