I am involved with SAR. I teach navigation to my team. I use to hide water bottles in an area, mark the location, and have the team map, plot a route, and find the "victim." Now, I have a lot of other people hiding things, so I don't have to get there 2 hours before my team to hide Mr. and Mrs. Aquafina.
Also, since in SAR you are looking for the little things that are out of place. On wilderness caches, I can usually find them w/o GPS, because I will track others that have been to the cache. It is a great and ongoing lesson. When you train your eyes, and continue to train them to find the item that is "out of place", then it becomes a lesson and a sport.