I realize that this is a highly subjective question but when should a boater step up from class III to IV or any level that is? Is it a cerain amount of years experience and/or a flawless run down a step below the desired class of run? My particular situation is I have been boating for almost two years and have a very solid roll which I use a lot playboating and river running. I have little apprehension running Brown's but I ran the Numbers and was quite scared the whole time. Granted the water levels were much higher than they are now--2000 cfs for the numbers-- and I was paddling a G Force 6.1 which I understand now was a poor choice. I was with some excellent paddlers one with over 10 years experience who are adept at chasing boaters stuff and the actual boater. I flipped each number but rolled up and then swam 5 while tagging a few rocks and being submerged for a good portion of the remainder of 5. I respect this sport tremendously now more than ever and was wandering when do you step up? Do you just know or what?