Req 7b7 — Map & Compass

A GPS is useful, but in cold temperatures batteries drain fast and electronics can fail. Knowing how to navigate with a map and compass is an essential skill for any backcountry or cross-country ski tour.

Reading a Topographic Map

A topographic (topo) map shows terrain in three dimensions through contour lines — lines connecting all points at the same elevation.

Key map-reading skills:

• Contour lines close together = steep terrain. Lines far apart = gentle terrain.
• Contour interval: each map states its contour interval (e.g., “20-foot contour interval”). Every line represents a rise or fall of that amount.
• V-shapes pointing uphill = valleys or drainages. V-shapes pointing downhill = ridges.
• Closed circles = hilltops or peaks. The innermost circle is the summit.
• Index contours are every fifth line and are marked with their elevation.
• Map scale (e.g., 1:24,000) tells you the real-world distance represented per inch or centimeter on the paper.

For ski touring: Read the topo before you leave. Identify steep sections (avalanche risk), flat travel zones, stream crossings, and your intended route’s high and low points.

Using a Compass

A baseplate compass (like a Silva or Suunto) has three essential parts:

1. Magnetic needle — always points to magnetic north.
2. Rotating bezel (azimuth ring) — marked in degrees from 0 to 360.
3. Baseplate with direction-of-travel arrow — points where you want to go.

Taking a bearing from a map:

1. Place the compass on the map, aligning the baseplate edge with your start point and your destination.
2. Rotate the bezel until the north lines on the bezel align with the north lines on the map.
3. Read the bearing at the direction-of-travel arrow (e.g., 285°).
4. Adjust for declination — the difference between magnetic north and true north. Your topo map will state the declination for your area.

Following a bearing in the field:

1. Hold the compass level.
2. Rotate your whole body until the magnetic needle aligns with the north arrow on the bezel (“red in the shed” or “putting Fred in the shed” are common memory tricks).
3. Walk in the direction the direction-of-travel arrow points.
4. Sight on a landmark in that direction, travel to it, and repeat.

Dead reckoning in a whiteout: If visibility drops to near zero (whiteout), you can navigate by bearing and pace counting. Know your pace count per 100 meters to estimate distance traveled.

Official Resources