Which scan method is essential for areas with restricted visibility?

The horizontal scan is essential for areas with restricted visibility because it allows for a thorough examination of the environment along a horizontal plane. This scanning method is particularly effective in situations where obstacles, low light, or other visibility limitations make it difficult to see objects directly in front or above. By scanning horizontally, personnel can detect threats or important features in their immediate surroundings without the need for a more extensive vertical viewpoint, which might not be feasible in such conditions.

In restricted visibility scenarios, utilizing a horizontal scan can enhance situational awareness and improve reaction times to potential threats. This method ensures that attention is focused on what is directly accessible and visible, thereby maximizing the opportunity to notice any critical information or dangers that may be obscured from a typical line of sight.