Plan a Day Walk

Map Reading and Navigation

Course 1 · Chapter 10 · Plan a Day Walk: Capstone

This is the final chapter. There is nothing new to learn; instead you will use everything from the course to plan one complete day walk, step by step, the way an experienced walker does at the kitchen table the evening before. A good plan is what makes the day itself calm.

The Planning Sequence

Work in the same order every time. Each step uses a chapter you have already met:

Step	Question	Skill from
1. Aim	Who is going, how fit are they, how long a day do you want?	Chapter 7
2. Route	What are the start, the turning points and the finish? Is the terrain suitable?	Chapters 1-3, 7
3. Legs	For each leg: grid references, distance, ascent, bearing	Chapters 2, 3, 5, 6
4. Time	How long does each leg take, and when do you arrive?	Chapter 6
5. Safety	Escape routes, catching features, hazards, weather, kit	Chapters 7-9
6. Limits	Turn-back time and the other reasons to turn back	Chapter 9
7. Record	Route card, shared with someone who will notice if you are late	Chapter 7

Our Worked Route

We will plan a round walk from a start point, out to a bridge, up to a col, on to a summit and back directly to the start. The map positions (in metres from the grid origin, with heights from the contours) are:

Point	Easting (m)	Northing (m)	Height (m)
Start	3000	5000	100
Bridge	5000	5000	100
Col	5000	8000	450
Summit	7500	9500	780

Remember These are practice coordinates on an imaginary map. On a real map you would read six-figure references (Chapter 2) and convert them to metres in the same way. The return leg here is a straight line for simplicity; a real return would follow a path or valley you had checked on the map.

Legs, Bearings and Times

For each leg we need a grid bearing (Chapter 5), a distance, the ascent (Chapter 3) and a time from Naismith's rule (Chapter 6): 12 minutes per kilometre plus 10 minutes per 100 m climbed. The whole job is a short loop.

import math

def to_min(t):
    h, m = t.split(":")
    return int(h) * 60 + int(m)

def to_clock(mins):
    return f"{mins // 60:02d}:{mins % 60:02d}"

def bearing(e1, n1, e2, n2):
    return round(math.degrees(math.atan2(e2 - e1, n2 - n1)) % 360)

def naismith(dist_km, ascent_m):
    return round(dist_km * 12 + ascent_m / 100 * 10)

# name, easting (m), northing (m), height (m)
points = [
    ("Start",  3000, 5000, 100),
    ("Bridge", 5000, 5000, 100),
    ("Col",    5000, 8000, 450),
    ("Summit", 7500, 9500, 780),
    ("Start",  3000, 5000, 100),
]

clock = to_min("09:00")
total = 0
for a, b in zip(points, points[1:]):
    dist = math.hypot(b[1] - a[1], b[2] - a[2])
    ascent = max(0, b[3] - a[3])
    mins = naismith(dist / 1000, ascent)
    total += mins
    clock += mins
    print(f"{a[0]:>6} -> {b[0]:<6} {bearing(a[1], a[2], b[1], b[2]):03d} deg {dist:5.0f} m +{ascent:3d} m {mins:3d} min  {to_clock(clock)}")
print("Walking time:", total, "min")
print("With 45 min of stops:", total + 45, "min, back at", to_clock(to_min("09:00") + total + 45))

# Start -> Bridge 090 deg  2000 m +  0 m  24 min  09:24
# Bridge -> Col    000 deg  3000 m +350 m  71 min  10:35
#    Col -> Summit 059 deg  2915 m +330 m  68 min  11:43
# Summit -> Start  225 deg  6364 m +  0 m  76 min  12:59
# Walking time: 239 min
# With 45 min of stops: 284 min, back at 13:44

Read what the numbers tell you. The route is about 14 km with 680 m of ascent and takes roughly four hours of walking, finishing around 13:45 with stops. The long final leg is the biggest single item, and it is a straight-line estimate, so a real path would be longer. Real walkers add a margin for that.

Grid bearing to compass bearing The bearings above are grid bearings. In the field you must adjust for the magnetic variation shown on your map (Chapter 4) before following one on a compass, adding or subtracting as the map tells you. Write both columns on your route card so you do not have to calculate with cold hands.

Safety Planning

Escape routes

For each leg, note the quickest way down or out: a track from the col, the road at the bridge. Check that each is a real path on the map.

Handrails and catching features

Choose a stream, wall or ridge to follow on each leg, and a feature beyond each turning point that tells you that you have gone too far.

Hazards

Look for steep ground, crags, river crossings and open exposed tops on the map, and plan around them (Chapter 3).

Weather and kit

Check the forecast for the summit, not the valley. Pack the kit list from Chapter 9, plus a spare layer for the highest point.

The Time Budget and the Turn-Back Time

Compare the finish time with the light. Say it gets dark at 16:30 and you want a one hour margin. The latest you should be back is 15:30, so a 13:44 finish leaves a comfortable margin of nearly two hours. The latest safe start would be about 11:00.

def plan(start, legs, stops, dark, margin=60):
    walking = sum(naismith(d, a) for d, a in legs)
    finish = to_min(start) + walking + stops
    latest = to_min(dark) - margin
    status = "OK" if finish <= latest else "TOO LONG"
    return walking, to_clock(finish), status

Then set a fixed point-by-point turn-back time as in Chapter 9: for each turning point, the latest time you can arrive and still get home with the margin. If you reach the col at 12:30 when the plan said 10:35, you are two hours behind and the summit is no longer sensible. Decide that now, at the table, not on the hill.

The Route Card

The route card turns the plan into a single page you can leave with someone. For each leg it holds the start and end points, the bearing, distance, ascent, time, expected arrival and the escape route. It also records the group, the vehicle, the kit, the planned finish and the time at which the person at home should raise the alarm.

def route_card(legs, start, escape):
    clock = to_min(start)
    print("From      To        Dist   Ascent  Time  Arrive  Escape")
    for name_a, name_b, dist, ascent in legs:
        mins = naismith(dist, ascent)
        clock += mins
        print(f"{name_a:<9} {name_b:<9} {dist:4.1f}   {ascent:5d}   {mins:4d}  {to_clock(clock)}   {escape[name_b]}")

legs = [("Start", "Bridge", 2.0, 0), ("Bridge", "Col", 3.0, 350), ("Col", "Summit", 2.9, 330)]
escape = {"Bridge": "back to road", "Col": "south track", "Summit": "retrace to Col"}
route_card(legs, "09:00", escape)

# From      To        Dist   Ascent  Time  Arrive  Escape
# Start     Bridge     2.0       0    24  09:24   back to road
# Bridge    Col        3.0     350    71  10:35   south track
# Col       Summit     2.9     330    68  11:43   retrace to Col

On the Day

Check the forecast again before leaving. If it is worse than the plan allowed for, choose a lower route or stay home.
Leave the route card with someone, and tell them when you are back.
Set the map to the ground at each turning point (Chapter 1) and confirm with a feature, not just the time.
Keep ticking off the card: note your actual arrival times against the plan.
If you fall behind, change the plan early: skip the summit, take an escape route. Do not try to catch up by hurrying.
When you finish, tell the person who has your card.

Review afterwards Compare actual times with planned times. If you were consistently slower, your personal pace is slower than Naismith's rule; adjust future plans. This is how the rule becomes your own.

Common Mistakes

Mistake	Fix
Planning the route for the best walker	Plan for the slowest or least experienced person
Forgetting stops in the time budget	Add time for food, photographs and navigation checks
Trusting straight-line distances	Measure along the actual path and add a margin
Leaving grid bearings uncorrected	Apply the magnetic variation and write both on the card
No escape routes for the later legs	Check one for every leg before you set off
Fixing the turn-back time on the hill	Set it at the table, from the light and the return time
Telling nobody the plan	Leave the card, and agree when to raise the alarm

Challenges

Exercise 1

Write functions bearing(e1, n1, e2, n2) (rounded grid bearing in degrees, 0 to 359) and distance(e1, n1, e2, n2). Use them on a three-leg route with corner points (1000, 2000), (4000, 6000), (4000, 9000) and back to (1000, 2000), printing the bearing and distance of each leg.

→ Solution

Exercise 2

Write plan(start, legs, stops, dark, margin=60) returning the walking time, the finish time and "OK" or "TOO LONG" against the time it gets dark less the margin. Use legs (3 km, 200 m ascent), (4 km, 400 m) and (5 km, 0 m), 45 minutes of stops, and dark at 16:30. Try starts of 09:00 and 13:00.

→ Solution

Exercise 3

Write route_card(legs, start, escape) that prints one line per leg with the names, distance, ascent, Naismith time, arrival time and escape route. Use the three legs and the escape notes from this chapter, starting at 09:00.

→ Solution

Quick Reference

Plan in order: aim, route, legs, time, safety, limits, record
Each leg: grid references, bearing, distance, ascent, time, escape route
Naismith: 12 minutes per km plus 10 minutes per 100 m of ascent, then add stops
Bearings: grid from the map, then correct for magnetic variation
Latest finish: dark minus a margin; the turn-back times are set at the table
Route card: left with someone, with a time to raise the alarm
On the day: compare the plan with reality, change it early, tell people you are back

Course complete You can now read a map, find a grid reference, understand relief, use a compass, take and follow bearings, estimate time and distance, plan a route, fix your position, cope with poor visibility and plan a complete day. The next step is to practise: take a short, easy walk, navigate it deliberately, and build up from there.