Reading an orienteering map

The single most confusing thing for anyone arriving from Ordnance Survey maps: white means forest you can run through, and yellow means open ground. On an OS map, white is broadly open and green is woodland. On an orienteering map the logic is different — the colours encode *how fast you can move*, not what is growing there.

These are set by the international mapping specification, which is why a map drawn in Finland reads identically to one drawn in Scotland.

Alongside the map you get a description sheet: a table of pictorial symbols, one row per control. It tells you the control number, its code (which must match the flag you punch), what feature it is on, which side of that feature, and often a size or a height.

The symbols are international and deliberately wordless. There are perhaps twenty you meet regularly — boulder, knoll, depression, path junction, stream bend, vegetation boundary, ruin, pit — and learning those covers the large majority of courses.

The habit worth building immediately: read the description before you leave the previous control, not when you arrive. Knowing you are looking for a small depression on the north side of a boulder changes how you approach the whole leg.

1. 1

   Step 1: Orient the map

   Physically turn the map so that north on the paper points north on the ground and the features line up with what you can see. Then everything reads directly: a bend to the left on the map is a bend to the left in front of you. Beginners read maps north-up while facing south and invert every decision they make.

   You will know it worked when: The map and the world agree.

2. 2

   Step 2: Thumb your position

   Fold the map small, hold your thumb on where you are, and move the thumb as you travel. It costs nothing and means you never have to re-find yourself on the sheet — which is what actually consumes time when things go wrong.

   You will know it worked when: You always know where you were thirty seconds ago.

3. 3

   Step 3: Navigate to an attack point

   Do not navigate finely for 600 metres. Pick something unmistakable near the control — a path junction, a pond, a distinct boulder — travel to it quickly and coarsely, and only then navigate carefully over the last 100 metres. Fine navigation over long distances accumulates error; this contains it.

   You will know it worked when: Errors stay small and recoverable.

4. 4

   Step 4: Aim off

   When heading for a control on a linear feature such as a stream or a wall, deliberately aim to one side of it. Then when you hit the feature you know with certainty which way to turn. Aiming straight at it leaves you at the feature with a 50/50 guess.

   You will know it worked when: No coin-flip decisions.

Beginners navigate by paths and vegetation. Experienced orienteers navigate by landform, and the reason is reliability: forestry work fells a plantation and the green areas change overnight, but the shape of the hill does not. Brown is the one colour on the map that is guaranteed still to be true.

The practical skill is reading a slope as a three-dimensional shape rather than as lines. Contours close together mean steep; a small closed ring is a knoll; a ring with tick marks pointing inwards is a depression. A re-entrant is a small valley running into a hillside and a spur is the ridge between two of them, and being able to see those from the map while standing in the terrain is the point at which orienteering becomes navigation rather than searching.

A useful drill: on a walk, stop and predict the shape of the ground ahead from the contours before you can see it. Being wrong is the useful part.