I just want to echo PP's sentiments. I have had training and experience in swift water rescue and it is a very dangerous enterprise, even with training. During the time I was active in SAR in Tucson, drowning was just behind falls as the number one cause of fatal injuries in that area. In the worst case, we lost nine to drowning in one incident. This is in desert country!

Teslin's pictures beautifully illustrate the more rational alternative. It is an immutable Law of Nature that streams become smaller as you ascend them (eventually)....