Swimming whitewater without life vests is extremely dangerous. On May 23rd Delia Chaffin, 65, and Ellory McCauley, 59, were running the North Platte River in Wyoming with a friend. None of the three wore life vests. According to the Associated Press, their raft was punctured when it hit a bridge pier. Chaffin and McCauley quickly disappeared underwater. The third paddler reached shore and called for help. The man was legally drunk and authorities cited him for operating a boat while intoxicated.
http://www.billingsgazette.com/index.php?id=1&display=rednews/2005/05/24/build/wyoming/20-raftingdeath.inc