I carry a Patagucci "Storm Front" back pack. It is waterPROOF and holds most everything I will need for the day away from the car/boat. Keeps my camera stuff dry even if I dunk. I usually leave it on the back and wade with a small bag (holds a couple of boxes for flies and leader etc.) or just use pockets.
This year I am going to tryout a SageBrush water proof fanny/shoulder bag for the photo stuff. Looks very promising.
One cast can change your day...maybe your life.