I work as the Northern Rockies representative for Kokatat and have been doing white-water boating since 1972, when I “fell into” a summer job as a guide on Idaho’s Middle Fork Salmon.
However it took a tragedy on Idaho’s South Fork Boise in 2001: to make me re-examine what I believed about survival time in very cold water.
May 5, 2001 two-couples launched their rented paddle raft on the very cold (estimated 40-45 degree F.) S. Fork Boise River, for a day trip on a 17 mile Class III+ section.
They had taken a rafting class at Boise State University and were wearing recommended clothing for a cold-water day: “Farmer John” wetsuits, neoprene booties and gloves, water-proof paddle-jackets, life-jackets, and helmets.
They hit a rock and “flipped” their raft at the entry to a long class III rapid. The four boaters then clung to their upside down raft until the end of the rapid. It is a fairly long rapid, with a number of large rocks, but takes less than 5 minutes to float through.
By the end of the rapid: two of the boaters were unable to respond to instructions, or swim to shore. They both died shortly afterwards of hypothermia or drowning.
Most experienced paddlers have a good understanding of what clothing they need for different weather conditions, and water temperatures. Many beginning and intermediate paddlers may need some advice.
Alicia has saved as PDF’s and furnished links to two articles I have written on the subject of cold-water clothing.
The first is a one page “cheat-sheet.”
The second is the five-page, fairly technical, research report that the above accident inspired me to write.