SAR Word of the Day

positive-declination (1)

Dec·li·na·tion
noun  / dekləˈnāSHən/
declinations, plural 

1. The angular deviation of a compass needle from true north (because the magnetic north pole and the geographic north pole do not coincide).

2.The horizontal angle between the true geographic North Pole and the magnetic north pole, as figured from a specific point on the earth. 

Six Steps to Becoming a Better Navigator

By Mark Sembrat

Step 1 – Pay more attention to everyday navigation tasks.

  • What’s the feel of the route?
  • How long until your next action point?
  • What do you look for to know you’re en route?
  • What do you look for that alerts you to an upcoming action point?
  • Pay extra attention when going someplace new or when you make a navigation error.

Step 2 – Learn to read maps

  • Visualize topography using various types of maps.
  • Locate action points.
  • Get the “feel” of the route from the information on the map.
  • Use a map as you navigate.
  • Ask where am I, and what happens next?

Step 3 – Learn to make a navigation story

  • Combine a starting point, route feel, action-point predictors, and action points into the “story” you plan to follow.
  • When you are first learning this skill, it may be useful to write or sketch your story.

Step 4 – Learn to use your navigation story

  • Learn to follow your story as you travel along your route. (You may want to pull out your map and notes to refresh your memory of the story as you go along.)
  • Learn to recognize when your story goes bad …

Step 5 – Build a toolkit of navigation skills and techniques

Learn to …

  • Recognize terrain features on a topographic map
  • Orient your map using the terrain and your compass
  • Use your GPS and plot the resulting coordinates
  • Use your altimeter to determine your location
  • Use your compass to determine your location
  • Work with speed, distance, and time

Step 6 – Practice, Practice, Practice!

  • Take both real and virtual hikes to improve your map skills.
  • Go to lots of new places, by road, by trail, and by cross country.
  • Return to Step 1, keep paying attention, keep learning.

Map and Compass Checklist

 

By Mark Sembrat

Do you have the hang of using a map and compass? Run through the whole procedure.  Remember the following.

  • Never use the magnetic needle or the declination arrow when measuring or plotting bearings on the map.
  • When taking or following a bearing in the field, always align the pointed end of the declination arrow with the north-seeking end of the magnetic needle.

Orienting a Map

  1. Set to 0 or 360 degrees
  2. Place compass on the map with the direction-of-travel line toward the north on the map.
  3. Turn the map and compass together until the north-seeking end of the compass needle is aligned.
  4. Compare information on the map with the field topography.

Taking (measuring) a Bearing in the Field

  1. Hold the compass level in front of you and point the direction-of-travel line at the desired object.
  2. Rotate the housing to align the declination arrow with the magnetic needle.
  3. Read the bearing at the index line.

Plotting (following) a Bearing in the Field

  1. Set the desired bearing at the index line.
  2. Hold the compass level in front of you and turn your entire body until the magnetic needle is aligned with the declination arrow.
  3. Travel in the direction shown by the direction-of-travel line.

Taking (measuring) a Bearing on a Map

  1. Place the compass on the map, with the edge of the base plate joining the two points of interest.
  2. Rotate the housing to align the compass meridian lines with the north-south lines on the map
  3. Read the bearing at the index line.

Plotting (following) a Bearing on a Map

  1. Set the desired bearing at the index line.
  2. Place the compass on the map, with the edge of the base plate on the feature from which you wish to plot a bearing.
  3. Turn the entire compass to align the meridian lines with the map’s north-south lines. The edge of the base plate is the bearing line.

Declination:  The difference between True North (T) and Magnetic North (M)—Use 15 Degrees. In this part of California . . .

  • True = Magnetic – 15
  • Magnetic = True + 15