Staff Rapids have long been a mysterious phenomenon in the world of whitewater. How are they formed? How do you navigate them? Where are the safe spots? What dangers lie beneath? Ben Koehler knows because he gets intimate with rivers. Especially rivers with rapids. He does so using a scuba setup, exploring the wild contours molded by flowing water. You can see that he can eddy out behind rocks (the slow-moving water where the current is blocked, creating “safe” spots), or simply do what the fish do and swim up river.