Map Reading and Adventure Training
Scale and distance
A map scale is a ratio. At 1:50,000, 1 cm on the map = 50,000 cm on the ground = 500 m, so 2 cm = 1 km. At 1:25,000, 1 cm = 250 m, so 4 cm = 1 km. Convert map centimetres to ground metres by multiplying by the scale's ground equivalent.
Grid references
Grid lines are numbered eastings (vertical) and northings (horizontal). Read right and up: easting first, then northing. A four-figure reference gives the square; a six-figure reference adds tenths. For square 1234, a point two-tenths right and five-tenths up is 122345.
Bearings
A bearing is measured clockwise from north in degrees. A magnetic bearing uses a prismatic compass; a grid bearing uses the map. Back bearing = forward bearing ± 180 degrees: add if the bearing is less than 180, subtract if more. Set the map by aligning grid north with compass north, allowing for magnetic variation.
Relief
Contours join points of equal height; close contours mean a steep slope, widely spaced contours a gentle slope. Spot heights mark exact points. Contour interval is the vertical distance between contours.
Worked example
A point in square 1234 lies 0.2 east and 0.5 north. Reasoning: easting = 12 + 0.2 = 12.2 → 122; northing = 34 + 0.5 = 34.5 → 345; six-figure reference 122345. Reading north first gives 345122, a different square.
Adventure training
Trekking, rock climbing, rappelling and rafting build courage and teamwork; the safety brief, buddy system and equipment check are examinable, not optional.
Traps
Reading northings first; using ±180 incorrectly; saying 1 cm = 1 km at 1:50,000; ignoring magnetic variation.