I've been having trouble posting photos, but managed to throw a few on here.
If you haven't checked out Primal Quest's Web site, the photos alone are worth the stop. They capture the drama of this grueling race - and the humor in which many racers face the extreme conditions. Just a sampling: (other photo credits to come, when I find them again.)
Racers wrestle gripping rapids while cruising on boogie boards by Side Light/John Nantes