A P.F.D. is the first line of defense against drowning for all participants and leaders. I or III is worn by each person. P.F.D.'s should always be worn when scouting rapids or working on the river bank. P.F.D. The P.F.D. as protection against immersion hypothermia. P.F.D.'s can increase survival times because they insulate the wearer.
Unnecessary swimming increases the rate of body heat loss.
This action tends to decrease heat loss, to increase survival times, and to keep morale higher. If rapids on a river generally fit into one of the following classifications, but the water temperature is below 50 F or if the trip is an extended trip into a wilderness area, the river should be considered one class more difficult. Easy rapids with waves up to 3 feet and wide, clear channels that are obvious without scouting. Some maneuvering is required. Rapids with high, irregular waves often capable of swamping an open canoe.