THE GUN ROOM

The compass is the most reliable navigational tool known to man. Next to a clear-thinking mind, it's the best insurance you can bring into country where an error can at the least cause you a measure of embarrassment and a sleepless night on cold ground. By periodically glancing at a compass, you can update your position relative to prominent landmarks or baselines such as rivers and stay found, as opposed to resorting to your compass only after becoming disoriented, which is a sure recipe for getting lost.

For simple direction finding, a pin-on bubble compass is all you need. But orienteering, or navigating with map and compass, is a more advanced skill.

Why bother with such "archaic" technology in the age of satellite positioning? For starters, a GPS unit is a gadget, more prone to mechanical failure than a simple compass. Its batteries are less likely to produce juice when the temperature is coldest and finding your way back to camp is crucial. Second, in mountainous terrain or forest cover, a GPS may not be able to locate enough satellites for accurate positioning. Furthermore, most can't tell you how to find a feature of land that's marked on a map. A compass can.

Prerequisite Skills: True North
Before you begin map and compass work, you must adjust for declination. This is the difference between "true" or geographic north, which is the top axis of Earth; and magnetic north, which lies in the Baffin Islands at the northern terminus of the planet's magnetic core (the direction your compass needle points). The declination is defined by an angle, marked off in degrees, at the bottom margin of your topographic map. Most orienteering compasses come with a declination adjustment dial. If yours doesn't, you can use a straightedge to overlay the map with red ink lines aligned with magnetic north, and use these for orienteering.

Advanced Skills: Plotting a Route
To travel from one spot on a map to another, align one of the long edges of your baseplate compass with your starting point and objective. Turn the housing until the N and S on the face align with one of the vertical lines on the map. If you've adjusted for declination by overlaying the map with lines corresponding to magnetic north, use one of these lines instead.

Read the course you want to take at the direction-of-travel arrow's base. Now fold away your map. Holding the compass in your outstretched palm, turn your body until the magnetic needle lies exactly over the outline of the orienting arrow. Follow the direction-of-travel arrow toward your destination.

In rugged or boggy terrain, straight-line travel to your destination is seldom advisable. Because of intervening swamps, ridges, or other obstacles, it's usually best to divide longer journeys into legs that take advantage of good footing. If you plot each leg in a notebook, with both the forward bearing and the back bearing‹that's your forward bearing plus or minus 180 degrees‹you'll be able to reverse your course at the end of the day. Also, bear in mind that if you stray a few degrees to either side, you may miss a small target such as a pond. Better to navigate first to a larger lake or pick a course that will lead you to an inlet stream, which you can track to your destination.

The following challenge is designed to test basic orienteering skills. The real test will come when you place a compass over a map of your area and follow the direction-of-travel arrow to that secret lake you've always wanted to fish. Whether you find trout there doesn't really matter. The satisfaction will be in glimpsing a sparkle of water through the trees and knowing you got there by your own wits. Better yet, you can get back home.

First Steps
For orienteering, you need a protractor-type compass with: (A) transparent baseplate; (B) rotating housing marked off in 360 degrees; (C) orienteering arrow; (D) direction-of-travel arrow.

1. To take a compass bearing, place the long edge against your current position and your destination. Rotate the housing until the N and S on the compass match the vertical lines on the map. Your bearing will be at the base of the direction-of-travel arrow.

2. In this example, your bearing is 9 degrees. Put away the map. Hold the compass at arm's length and turn your body until the magnetic needle lies over the orienteering arrow. The direction-of-travel arrow will point to your objective.

The Challenge
Use your compass to plot the following course on the map below. We've marked the bearing points for clarity. By aligning with the red lines, you'll adjust for the 15 degrees east declination. Jot down all bearings you've taken, plus the back bearings for your return trip.

Bearing A. Starting at the campground on the northwest end of Horseshoe Lake, take a bearing that will take you to the center of the crescent-shaped lake that lies a short hike away to the northeast. Bearing B. From here, take a second bearing toward the small marsh that lies just east of the outlet stream of Robinson Lake.

Bearing C. Hike up the stream to Robinson Lake, then hug the western shoreline until you reach the small isthmus of land that separates it from its sister lake just to the east. From here, take a bearing to the outlet stream of the two small ponds that lie to the north.

Bearing D. Now walk upstream (east) past the first pond and up the outlet to the second pond. Take a northerly bearing from this pond to the easternmost of the two islands in the large unnamed lake that lies to the north. This island is your goal.

Navigate there‹and back‹and you can find your way in the wild.

Answers
(A) 42 degrees
(back bearing 222 degrees)

(B) 82 degrees
(back bearing 262 degrees)

(D) 20 degrees
(back bearing 200 degrees)