Weather, time and navigation

The parent page's sky-reading is sound and its navigation methods are the right ones. Two of them need a British correction, and one free resource is missing that beats everything on the page.

The watch method is wrong in summer

The hour hand at the sun, halfway to twelve is south, works on solar time. British Summer Time is an hour ahead of it.

So for roughly seven months of the year, from late March to late October, the method as written puts your south out by about fifteen degrees, which over any distance is a long way wrong.

The correction is simple and almost never stated:

• In winter, on GMT: point the hour hand at the sun, and south is halfway between the hour hand and twelve.
• In British Summer Time: subtract an hour first. Point where the hour hand would have been an hour earlier, then bisect to twelve. Or bisect to one o'clock instead of twelve, which is the same thing and easier to remember.

The shadow-stick method has no such problem and is the better one to rely on. Mark the tip of a shadow, wait fifteen minutes or more, mark it again, and the line from the first mark to the second runs roughly west to east. It needs no watch, no time zone and no arithmetic, and it is the parent page's own first suggestion.

Polaris at night is exact and needs no correction at all. Find the Plough, take the two stars at the end of its pan, follow the line about five times their separation, and the moderately bright star you reach is Polaris. That direction is north to within about a degree.

The forecast that needs no internet

The Shipping Forecast is the best weather resource in this chapter and it is free, four times a day, on a radio.

It is broadcast on BBC Radio 4, including on 198 long wave, which carries across the whole United Kingdom and a long way beyond, from very few transmitters. That makes it the single most resilient weather information available to a British household, and it works on the cheapest wind-up radio.

It takes ten minutes to learn to read, and it repays that permanently:

• Find your sea area. Anyone in Britain is next to one, and coastal weather arrives inland shortly afterwards.
• The order is fixed: gale warnings, general synopsis, then each area with wind, weather and visibility. The rhythm is what makes it memorisable.
• The general synopsis is the useful part inland. Low pressure, where it is, and where it is going.
• Falling and moving quickly means wind. A deepening low approaching from the west is tomorrow's problem.

Also print a tide table if you are anywhere coastal, and sunrise and sunset tables for your latitude, exactly as the parent page says. Both are free, both are unavailable when you want them, and both are one sheet of paper.

Reading British weather specifically

The parent page's sky signs are correct and Britain adds one dominant fact.

Our weather comes from the west and south west. That is why red sky at night genuinely works here: a red sunset means clear air to the west, which is the air arriving next. It also means the useful direction to look is west, and that the sky behind you tells you about weather that has already gone.

A cheap barometer earns its place, because the trend matters far more than the number. Tap it, note it, and look again in three hours. Falling is what you are watching for.

And the parent page's folk indicators are not superstition. Smoke lying flat rather than rising, distant sounds carrying unusually well, and aching joints all track falling pressure and rising humidity. They are crude, they are free, and they correlate.

Declination, which barely matters here now

Magnetic declination in Great Britain is currently small. It passed through zero in recent years across much of the country and is drifting east, so for practical walking purposes magnetic north and grid north are close enough that the difference will not lose you.

Two caveats that do matter:

• It varies with where you are and it changes over time. An old map's stated declination is out of date, and the value differs between Cornwall and Shetland.
• Local iron does more damage than declination. A compass near a car, a fence, a phone, a rifle or a steel-framed building will read badly wrong. Step away and take the bearing in the open.

So do not spend effort on declination arithmetic in Britain. Spend it on the two things below, which is where people actually get lost.

The two skills that actually stop you getting lost

The parent page names both and they deserve emphasis, because everything else on the page is direction-finding and these are navigation.

Handrails. Navigate by unmissable linear features: a river, a ridge, a wall, a road, a fence line, a power line. You cannot walk past a river. Following a handrail is slower than a straight line and it removes the possibility of being lost, which is the trade worth making every time.

Your pace count. Walk 100 metres on flat ground and count your double paces, the number of times your right foot lands. Most adults are somewhere in the sixties. Write it on the map. Then you can measure distance in the dark, in fog, on a featureless moor, with no equipment at all.

Add a third: the catching feature. Decide in advance what you will hit if you go too far. A road, a stream, a wall. When you reach it, you know you have overshot and by roughly how much, which turns being lost into a correction.

Practise all three on an ordinary Saturday, on ground you know, in daylight, with a paper map. That is the parent module's navigation day hike, and it is the one drill in this chapter that cannot be replaced by reading.