Assuming you are going to be renting your gear I will skip the usuall list of equipment that should be attached to your Personal Floatation Device. Any tool that you take after the trip should be dried out and lubricated. Don't have 100% confidence in belt cases or your pockets. I usually double secure my gear by using lanyards. That goes for my knife, Wave, lighter and flashlight. I would stash couple of high energy bars in my pockets. Water "sucks" a lot of energy out of you. Also plenty of water is important. If you fall into the river turn around and go down with the current legs first. That way you will absorb and impact from dead trees or rocks. When you reach pool of calm water make your way into the boat or to the bank of the river. Always wear your PFD. I saw excelent swimmers going under like rocks. Try avoiding glass containers.