Map & Compass Navigation: Scales, Grid References, Bearings, Declination & Slopes

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Convert map centimetres to ground kilometres and back for four different scales, turn a map area into square kilometres and work out the scale of an unknown map.
• Split 6- and 8-figure grid references into eastings and northings in metres with LEFT and MID, build a reference back from GPS metres with INT and TEXT, and measure the straight-line distance between two points.
• Calculate the grid bearing of every leg of a night course from coordinates with ATAN2, keep it between 0 and 360° with MOD, add the back bearings and the leg and course lengths.
• Update a fictional declination to the year of the hike, convert map bearings to compass bearings and back with the grid–magnetic angle, and keep every result between 0 and 360°.
• Turn contour counts and map millimetres into height differences, horizontal distances, slope percentages and angles, name the steepest leg and colour the legs that break the school's fictional slope mark.
• Turn counted paces into metres with a calibration and a terrain factor, split each leg into east and north parts with SIN and COS, and find the final position and the distance back to the start.
• Turn a bearing error into metres off course with TAN, compare the error cone with the width of each target, decide where to aim off, and calculate the aim-off angle and the number of legs that need it.
• Build a complete navigation log for a fictional score event: leg distances, grid and magnetic bearings, leg times with a pace rule, arrival times and a position plot of the whole course.