Check out this shot of Brian Vickers Kayaking at the USNWC.  This is from a trip to the whitewater center in Charolette NC.  I thought it was awesome that he came out to try kayaking through class II-III whitewater on his first day.  He was a natural at the sport hitting rolls his first time kayaking.  Brian was also quite friendly, and showed that even though he might be used to going 200 mph in a NASCAR race car, he was toally game when it came to trying out the sport of whitewater kayaking- and he learned quickly from good kayak instruction.  If he can do it, you certainly can!  Go for it!