Plotting: the skill the whole sport is decided by

The organisers do not give you a route. They give you a description of one, in a form designed to take work to decode, and your job is to convert it into a line you can read out to a driver one instruction at a time. Most of that conversion is grid references, and a grid reference is a coordinate on a printed sheet — nothing more mysterious than that.

What makes it a sport is the clock. The reference itself takes seconds to plot at a table and considerably longer on a knee under a map light with the car already moving, and you have a schedule to keep and a driver waiting to be told which way to turn at a junction two hundred metres ahead. So the skill being trained is not accuracy. It is accuracy at a speed that leaves attention spare, and the only way to get there is to make the mechanical part automatic first.

That is what this guide is for. Everything below can be practised at a kitchen table with a map, a romer and a pencil, and should be, because doing it for the first time in a car at midnight is how people conclude they cannot navigate.

What you are converting

Numbers into a line

Where to learn it

A kitchen table

The actual target

Fast enough to have attention spare

Written in

Pencil, always

A romer is a small printed scale — usually a corner cut into a plastic card, marked for a specific map scale — that reads the last digit of each half of a reference without arithmetic. It replaces estimating tenths by eye, which is fine at a table and unreliable at speed. Check it matches your map: a 1:50,000 romer on a 1:25,000 map is wrong by a factor of two and reads perfectly plausibly.

1. 1

   Step 1: Split the reference in half

   Six figures is two threes. The first three are the easting, the second three the northing. Say them to yourself split before you touch the map — this alone prevents most reversals.

   You will know it worked when: You know which number is which.

2. 2

   Step 2: Find the kilometre square from the first two of each

   Easting along the bottom, northing up the side. Put a fingertip on the bottom-left corner of that square and leave it there.

   You will know it worked when: The right square, with your finger in the right corner.

3. 3

   Step 3: Seat the romer corner in that corner

   The romer's corner sits on the bottom-left corner of the square with the scales running along the two edges. This is the mechanical bit and it is worth doing identically every time so your hands stop thinking about it.

   You will know it worked when: The romer is placed the same way it will always be placed.

4. 4

   Step 4: Read the third digits off the two scales

   The last digit of the easting along the horizontal scale, the last digit of the northing up the vertical. Where they meet is the point, to 100 metres.

   You will know it worked when: A point on the map.

5. 5

   Step 5: Mark it small, in pencil

   A tiny dot or a short tick, not a circle. Circles obscure the junction you are about to need to read, and everything you mark tonight will be rubbed out.

   You will know it worked when: A mark you can still see the map through.

6. 6

   Step 6: Say it back before moving on

   Read the reference off your own mark and check it against the paperwork. It takes two seconds and it catches the transposition that would otherwise cost you a passage check and twenty minutes.

   You will know it worked when: A plot you have checked once.

• Plot ahead, not to the current junction — Stay two or three instructions in front. A navigator working on the junction they are arriving at is already late, and the driver is guessing.
• Give the driver one instruction at a time — Direction, and a distance or a landmark. Not the reasoning, not the next three, and never the map. A driver holding four instructions in the dark will use the wrong one.
• Keep the map board still and the map oriented one way — Rotating the map to match the car is a hiking habit and it costs you the grid. In a car the map stays north-up and you do the translating.
• Own the light — Bright enough to read fine print, angled so none of it reaches the windscreen. A driver whose night vision you have destroyed is a bigger problem than a wrong turn.
• Write the schedule where you can see it without turning a page — Due times at controls are half the job. Anything you have to hunt for is something you will stop doing when it gets busy.
• Pencil, and a sharpener you can reach — Unromantic and decisive. Every plot is provisional, and a navigator with a broken point is a passenger.
• If you are lost, say so immediately — The cost of admitting it early is a few seconds. The cost of admitting it late is the rest of the section. Crews that recover well are crews where this is normal rather than embarrassing.

The last point is where this guide stops teaching. Recovering from a lost position — deciding whether to backtrack, rejoin ahead, or take the penalty and get to the next control on time — is a judgement made under time pressure with incomplete information, and everybody makes it badly for a season. It is the half of the sport that separates a fast navigator from an accurate one, and it is learned in the car with somebody experienced next to you, which is one of several reasons the sport tells beginners to navigate before they drive.

1. 1

   Step 1: Buy the sheet your local events use

   One 1:50,000 sheet covering the area your club runs in, and a romer to match. Under £25 and it is the only equipment this whole guide needs.

   You will know it worked when: You own the playing field.

2. 2

   Step 2: Plot fifty references to places you can verify

   Pick features off the map, write down their references, then plot them cold an hour later and check. Fifty is not many and it is enough to make the romer automatic.

   You will know it worked when: Plotting without counting.

3. 3

   Step 3: Then do it against a clock

   Thirty seconds a reference, then twenty. Speed is what you are training, because the accuracy is already there by now.

   You will know it worked when: Fast enough to have attention spare.

4. 4

   Step 4: Plot in the passenger seat, in daylight

   Somebody else driving, map board on your knees, no pressure and no schedule. This is where you find out about motion sickness, which is the reason a lot of people cannot do this and is much better discovered here.

   You will know it worked when: You know whether the moving part suits you.

5. 5

   Step 5: Marshal an event before entering one

   Standing at a control shows you what a time control and a passage check actually look like from the other side, which makes the paperwork stop being abstract. It is also how clubs meet you.

   You will know it worked when: The event makes sense before you compete in one.

6. 6

   Step 6: Then enter a 12-car

   Twelve cars, an evening, £15–£30, and organisers who expect novices. Read the event regulations first — they specify the maps, the timing and the blackspots, and exclusions almost always come from something that was written down.

   You will know it worked when: A first event you were ready for.

• Do I need a romer, or can I estimate? — You can estimate tenths by eye and it is fine at a kitchen table. It is not fine at speed in a moving car, which is where the sport happens — estimation errors are small, plausible and consistent, so you discover them at a control that is not there. A romer costs a few pounds, removes the arithmetic entirely, and must match your map scale: a 1:50,000 romer on a 1:25,000 map reads perfectly plausibly and is wrong by a factor of two.
• Which comes first in a grid reference? — Eastings, then northings — the number across the map before the number up it. Ordnance Survey's mnemonic is "Along the corridor, then up the stairs". Reversing them is the commonest plotting error there is, and it produces a reference that looks entirely reasonable and puts you somewhere else. Splitting a six-figure reference into two threes and saying them to yourself before touching the map prevents most of it.
• How precise is a six-figure reference? — Within 100 metres. A four-figure reference identifies a 1-kilometre square, and adding a digit to each half divides that square into a ten-by-ten array, which is the resolution rallies run on. One thing to get right from the start: a grid reference always refers to the bottom left-hand corner of its square, not the middle, and plotting to the middle is a consistent hundred-metre error.
• How do rally navigators plot so fast? — By having made the mechanical part automatic long before the event, so that all their attention is available for the puzzle. There is no technique for going faster — there is only having done it enough times that you are not counting squares. Fifty references plotted at a table, then fifty against a clock, is the whole method, and it is why this is learnable without a car.
• What if I get lost? — Say so at once. The judgement about what to do next — backtrack, rejoin ahead, or accept the penalty and make the next control on time — is the half of this sport that a guide cannot teach, and everybody makes it badly for a season. What can be said is that the cost of admitting it early is seconds and the cost of admitting it late is the section, and that crews who recover well are the ones where saying it is routine rather than embarrassing.
• Can I practise this without joining a club? — Entirely. Every convention here is Ordnance Survey's rather than the sport's and applies identically to hiking and orienteering, so any map and any afternoon will do. What a club adds is the part you cannot practise alone: what a control looks like, how the paperwork behaves, and a seat in a car with somebody who has done it. Marshalling an event first is the traditional route and it is still the best one.