Because their attention is focused on or near the ground, they are often misled by subtle terrain changes. Attempts to return to familiar ground only puts them further out of contact because of their complete disorientation. These circumstances usually put them at high risk for survival. Generally, they are very well oriented. The reason they are overdue is most often accident related, such as slipping into the water, falls over cliffs trying to move up or down stream, or swept off feet in fast moving water.
Primary factor is weather or hazardous conditions.
A very high percentage in this category is boat related. Often this will be a recovery mission. Hunters Hunters tend to concentrate on game more than on navigation. In the excitement of pursuing game, they are often led into deadfall areas, boulder fields, underbrush, and deep snow with little regard for exhaustion or navigation. They tend to over-extend themselves into darkness and push beyond their physical abilities.