One way to mark your location and communicate with Rescue Assets is to create geometric patterns that can be visible from sky. This shirt depicts the patterns used by international rescue organizations. These letters should be constructed on a clear patch of ground, with as much contrast between the symbols and backdrop as possible. Bright strips of parachute or pieces of dark wood on a light sand beach are good examples of this principle. In snow, this can be accomplished by walking or dragging an object to create a depression in the shape of the symbol. Also, remember to make the symbol as large as you can — at least 10 feet wide is recommended.