The activity includes 5km of whitewater rafting. You can extend it to 7km for THB 500 or 9km for THB 1000. The more exciting rapids are really only found on the 7km to 9km options, so seriously consider the length you want to raft. Also, the ATV ride lasts about 30 minutes. If you wear long pants, they may get dirty, but there's water available to rinse them off afterwards.