I'll second the power of even a mild river. This reminds me of a drift boat wreck I observed at the mouth of the West Fork of the Satsop in the 60's - a couple guys were not being careful and got blown in too close to the bank where the East Fork comes in. They made the classic mistake of trying to stop themselves by grabbing branches, and that boat went over so fast I wasn't sure I had seen it disappear, until two bedraggled guys washed up on an island just downstream. It was single digit weather and those dudes would have frozen quick - I couldn't row back upstream so I blew the hole I was in to get help, found a sled a half-mile below me, he ran up and rescued them, then tried to pull out their boat but couldn't budge it away from the log jam it was up against. Said they were pretty blue and could just barely get up the bank and into their rig. Worst of all though was the sledder told me he hooked a nice fish on the way down - in the bottom of the hole I blew to save those crackers