When I hike in I carry my waterproof gps. Mark the trailhead and the spot where I get to the river. I take my waders and wading boots out of the pack and stash it and the rod tube out of sight of canoers. Then I just carry the gps in a vest pocket. Before I had a gps I would inflate a balloon and tie it to a branch hanging over the water a ways away from my gear. I still carry a compass and try to hike in on a fairly straight line if I'm off trail. Coming out due East or whatever from the pack should put me in sight of the car if the electronics fail.