for the waypoints based on the rivermaps GC book. Just down load them and load into your GPS, I am not a GPS expert, but they should work on even a old model GPS.
If you do not have your original GPS manual see if you can google to find it and/or look at some of the gps message boards for help.
by the way I think most of those rivermaps are water resistant. When I did GC a year or so ago, I just stuck the rivermaps book on top of my cooler under a cam strap.