I feel we are greatly underutilizing the power of the GPS in the truck problem. Using trackback is great unless you are on the last 10 miles of an 80 mile loop. Sure, you can walk a straight line to the truck. Until you run into a canyon or an arroyo you can't cross. There are all sorts of scenarios where the GPS pointing to the truck can leave you lost for a long time.

Why not use the GPS in a more powerful way? To locate where you are on the map. Since you have the truck as a waypoint, you have a distance and a bearing to the truck. An azimuth from the truck is 180 out. So if the bearing is 020 at 5 miles, you are on an azimuth of 200 at 1 miles. (You are SW of the truck)

Then it's a simple matter to orient the map. Line up the compass and draw a line that runs through your exact location. Then use the distance on the GPS and measure how far along the GPS you are.

I'm beginning to think a protractor is a part of my essential items. One printed on overhead projector plastic would be almost weightless and you can see through it which is a big advantage. Still, they need training and practice, too.