Road vs. Topographical Maps
Activity: Reading a Map with Web Rangers
Pacific Crest Trail Maps using Halfmile’s Maps
Finding Direction without a Compass
Navigation by the sun
The simplest and the most fundamental method for the map and compassless natural navigator is to use the sun. The sun rises in the east and sets in the west – roughly speaking. Note: The exact point along the horizon at which the Sun rises or sets varies throughout the year.
When it reaches its highest point at noon, its direction will be either south (northern hemisphere) or north (southern hemisphere). In winter, the sun is lower in the sky so you will notice shadows are long.
Sun Shadow Method
The sun moves across the sky from east to west and its shadow gradually changes in length which is what makes this direction finding method work.
- Clear a flat area of dirt or sand. Grass will work, but not as well.
- Find a stick about 2 or 3 feet long and stick poke it into the ground so it stands up.
- Get another small stick or pebble and place it exactly on the end of the shadow line.
- Eat a trail bar or relax for a half hour.
- Place another stick or pebble at the end of the new shadow. If you have time, wait another 1/2 hour and repeat.
- The line between the two pebbles runs east-west direction with the first mark being west and the second being east.
- If you are in the northern hemisphere, North direction is perpendicular to the east-west line heading away from the sun. It’s South down under.
In the northern hemisphere, the location of north can be determined by the North Star. The North Star, also known as the Pole star, is a valuable navigation aid because it’s located almost above polar north. The North star is not a very bright star, but unlike the other stars, it remains at a fixed location in the sky.
In finding the North Star, the Big Dipper (Ursa Major) and Cassiopeia (shaped like a W) are helpful. Neither of these constellations ever sets and they are always visible on a clear night, however, they are not always in the same place. The position of the stars in the sky depends on the time, date and geographical position (latitude and longitude). You probably have noticed how stars appear to move across the sky during the night. The reason for that is due to the Earth’s rotation around its axis. That’s also the reason the sun moves across the sky in the day. That means the picture you see on this page probably does not match the sky you are viewing, but that is an easy fix as you can just rotate the image.
To locate north:
· Find the Big Dipper in the sky. Follow the edge of the cup 5 times its length toward a medium bright star. You have found the North Star, which is virtually north.
· To double check that it’s really the North Star, locate Cassiopeia. The North Star resides halfway between Cassiopeia and the Big Dipper.
Navigating by moss
The old saying that moss grows on the north side in the northern hemisphere is only partially accurate. Moss and lichens do not necessarily thrive where they receive the most shade, but, and this is important, where the moisture is retained the longest. Humidity is an even greater factor than shade.
Each locality has its difference in climate, and you should determine for yourself which side retains moisture the longest in your particular area. Only in this way can mosses and lichens be a valuable guide to direction.
How to Use a Compass
Step 2: Turn the compass until the north arrow on the compass’s face is aligned with the north end of the pointer. You are now aligned “north.” Observe the letters on the compass: N is north, E is east, S is south, W is west.Northeast, southeast, southwest, and northwest will also be present.
Step 3: Next, look at the numbers. These are degrees, another form of measuring compass direction.
Step 4: Turn and face any direction. Hold one hand out flat and place the compass on your palm. Point the arrow on the baseplate in the direction you’re facing.
Step 5: Turn the dial on the compass until the north-facing arrow is aligned with the pointer. Now read the degree mark that the index line crosses. This is your direction in degrees.
Step 6: To find your bearing, place the map on the ground and find where you want to start and end. Place the compass so that it matches both points. Turn the dial until “north” points the same direction as the north indicator on the map. The index on the baseplate should now line up with the correct bearing on the dial. Turn the compass in the correct direction.