As I am writing these land navigation pages, the first episode of this season’s Amazing Race is playing on television. In this episode, the contestants are told to use compasses to find buried clues. All the contestants struggle with the directions and or the compasses. Some struggle a little, but most struggle a lot. In the middle of this great effort, one of the female contestants utters excitedly, “The sun rises in the west and sets in the east.”
Of course, she was wrong, but I would bet this is the first time in years she had even thought about the rising and setting sun. Life today is an indoor activity. Video games, television, pay-per-view movies, the Internet, and many other things occupy most of our time. We hardly notice the sun much less sit long enough to watch its plodding progression through a cloudless sky. We have become unfamiliar with the outside world, and the greatest loss is experience which builds knowledge.
One day, go outside and spend some time just observing. Watch the sunrise, notice the sun’s track across the sky, and then note where on the horizon it sets. Notice your shadow as it moves around you through midmorning, midday, and afternoon.
Moreover, as you drive or move about outside doing chores and whatnot, keep taps on the sun. Notice your shadow in relation to north, south, east, and west. Pay attention to how your shadow falls, morning, noon, and night. This is especially true while you are in familiar territory. Noting these things while in familiar places helps you keep up with north while trekking through unfamiliar.
Twice a year, on the vernal and autumnal equinoxes (spring and fall equinoxes), the sun rises due east, 90-degrees, and sets due west, 270-degrees. This is true all over the world except the poles, where the sun does not rise or set but remains in the sky all day over the horizon (which I would like to see at least once before I die).
Every day before and after the equinoxes, the azimuths of the sunrises and sunsets shift either north or south of due east/west by 0.257-degrees. After about 90 days, the azimuths of the rising and setting sun reverses and starts back toward due east/west.
So, for about forty days, twenty days before the equinoxes and twenty days after the equinoxes, the sun is within ten degrees of due east/west at sunrise and sunset. So, for instance, from the first week in September to mid October 2014, dead reckoning easterly or westerly directions according to the rising and setting sun is fairly accurate.
Depending upon your location, the sun can rise and set well north and south of due east/west during the summer and winter. At the equator, the sun rises and sets no more than about 23 degrees north or south of due east/west during the summer and winter solstices.
However in the Bitterroot Mountain Range, Montana, the sun rose and set some thirty-five degrees north and south of due east/west during the 2014 summer solstice. The father one travels north and south of the equator, the farther the sun rises and sets south and north of due east/west.
When using the rising or setting sun for a directional reference, always keep the time of year in mind, and make the appropriate adjustments.
At and above the Arctic Circle, sunrise and sunset is well to the south until the sun remains in the sky all day. It’s the same for the Antarctic, except as summer comes on the sun rises and sets well to the north. (An intense knowledge and practice of land navigation and a specific study of Arctic/Antarctic navigation are warranted before wandering through the land of endless sunshine and shadow).
In the northern hemisphere, above the 23rd Parallel (Parallel = line of latitude), the sun at its zenith casts shadows true north—always exactly true north. Remember, this is not noon by your watch, because watches are set to time zones and not necessarily the zenith of your location, and daylight savings time moves time ahead of the sun’s zenith. Shadows in the southern hemisphere below the 23rd Parallel always point south at the sun’s zenith.
At the equator, shadows always point north after September’s autumnal equinox and south after the June’s vernal equinox. During these equinoxes, shadows lie below whatever is casting them, because the sun is directly overhead.
Between the two 23rd Parallels, the shadow’s direction is dependent upon the time of the year the sun is directly overhead. For instance, the sun is directly overhead in Darwin, Australia about forty-eight days after the autumnal equinox and about forty-eight days before the vernal equinox.
Don’t just cast a glance at your shadow and assume true north. Think about what you are doing. Also, think ahead. Note the particulars concerning your location and time of year before you strike out into the wilds. You can lose your compass and map, but you cannot misplace knowledge; and a knowledgeable navigator is a stress-free navigator.
Shadows move eastward as the sun travels westward. Shove a stick in the ground and mark the tip of the stick’s shadow with a rock or a coin from your pocket. Wait a few minutes, ten, fifteen, or thirty, and then mark the shadow tip again. Draw a line between the two marks. The first mark is west and the second mark is east. This will give a general indication of east and west. It’s a general indication, because the sun passes through the sky in an arch. Therefore, when you mark shadows in the morning, the east/west line is somewhat askew northeast to southwest, and when you do it in the afternoon, the east/west line is askew southeast to northwest.
Notwithstanding, to find true east and west, shove a stick into the ground, and then make the first mark ten to sixty minutes before the sun’s zenith. Then wait an equal amount of time after the zenith and make the second mark. Draw a line between the two marks. This line is due east and west. This works during any season anywhere in the world. (The top of the sun’s arch is the zenith, so making two marks of equal time before and after the zenith catches the arch on equal opposite sides of the arch.)
During overcast days, sunrise brightens the east before it brightens the entire sky. You’ve got to get up early to catch this fleeting indicator. The western sky is the last to darken at sunset.
The prepared navigator is rarely perplexed, so be sure to mark north, south, east, and west while the sun is shining in case the sun does not come out tomorrow. Keep in mind, singing, “The sun will come out, tomorrow,” doesn’t always work.