another one i could mention, just a handy one... obviously take a pencil for recording when you arrive at your waypoint and turning points. I use a old style pencil (not a clutch pencil, although i do have one as a backup), and i've roughly marked out a scale on it, to measure against the wac without getting out the proper ruler. Also, i have taped a string to it, bright pink builders line, and tyed it to my kneeboard.. saves it falling on the floor.