Whitewater kayaking suburban creek almost hit somebody what to do?

We were kayaking a creek called Sweetwater creek in suburban Atlanta and when we started out it was not crowded at all. This creek has a section that has class 3 rapids and the rapids are one after another. We were making our way from rapids to rapids and before we knew it we were in the middle of a whole bunch of people just hanging out in the river. The way the river is makes it hard to choose a path around the people so we ended up kayaking right next to them. We were yelling at them and telling them heads up but they just stared and wouldn't budge. We never hit anybody and maintained our distance at least two or 3 feet Away from them but it was a challenge we were hugging rocks and really fighting to not hit anybody. There wasn't much we could do to just stop and wait for them to move because the river just kept taking us to the next gr

Group of people hanging out in the rapids. What to do in a situation like this. I don't want to hit anybody and I know I won't always be able to look ahead around the corners to make sure nobody is in the river. Should I just go around blowing a whistle hoping nobody gets in my way when I'm barreling down a river? I can't find anything online that describes what to do and who yields to who