Rivers are big and fun. And big and kind of dangerous, depending on your level of comfort. Well, these guys–most of them pro-level paddlers–have a supreme level of comfort, as they so deftly show by squirting these whirlpools on Eastern Canada’s Ottawa River. The whirlpools are so powerful, they actually swallow full-volume river-running boats. The one hard rule when paddling whirlpools? Never exit your boat. Bad things will happen. Of course that’s easier said than done. Maybe avoid whirlpools all together, then?