Cold water is the bane of white water rafting in Washington and Alaska. It is the reason we wear wetsuits through June, and have our customers wear them nearly all of the time. It is the reason some guides and outfitters swear by drysuits, even when the air temperature is climbing into the 90s.
It is remarkable Washington's white water outfitters and guides have as good of track record as they do. The state's records of water-related fatalities show that nearly one hundred per cent of the victims were either a) not wearing a lifejacket b) improperly wearing a lifejacket c) inebriated or had alcohol in their system or d) both. The fact that commercial outfitters in the state have their customers wear life jackets all of the time and do not encourage on river drinking and provide neoprene goes a very long way toward stacking the odds in our favor.
Not wearing a lifejacket on moving water, especially in moving water where there is the opportunity for an unscheduled swim, is insanity. And even more so, with frigid moving water where the ambient air temperature is not conducive to rapid heat recovery.
On Washington's glacial and snow field fed streams and rivers, if you are, at minimum, dressed in neoprene and wearing a personal flotation device, you have increased your odds of survival immensely.
In addition to your neoprene wetsuit and boots, it is essential to add a 'splash' jacket, a layer or several layers of varying thicknesses of synthetic, wicking fibres, and a warm, synthetic or wool ski cap. Guides will be seen quite often with 'splash' pants as well. If worse comes to worse, and you arrive at the launch site on an overcast day on one of the Northwest's vaunted snow-fed whitewater runs, with nothing but the clothes on your back, it has been proven to be better to wear nothing but the neoprene with the life jacket than to count on cotton clothing --- of any kind --- to retain any heat.
The fun increases however, the better you are prepared.