Field notes 4 MIN READ
The London Marathon, drawn
One of the few marathon courses that is instantly recognisable as a shape. What makes it draw well, and the one section that always looks wrong.
Most marathon courses are unrecognisable as drawings. London is one of the exceptions.
The river does the work
The course tracks the Thames for long stretches, and the Thames is one of the most legible shapes in any city. Even without labels, the drawing reads as London: the big bend, the run along the north bank, the crossing at Tower Bridge.
This means a clean line print works here where it fails for other city marathons. You do not need street names for somebody to know what they are looking at.
The section that always looks strange
The loop through the Isle of Dogs and Canary Wharf.
On the ground it is the part where the crowd thins and the buildings close in. On paper it is a knot — the course doubles back on itself several times in a small area, and at poster scale those returns sit almost on top of each other.
Two things make it worse. Tall buildings are the worst possible environment for GPS: signals bounce off glass facades and the receiver computes positions that can be tens of metres out, sometimes inside a building. And the density means any error is drawn at the same scale as real turns.
The result is a small tangle around 24 km that looks like a recording fault and is mostly the course.
We do not clean it up. Snapping the line to the street network would tidy it and would also replace your race with a map of the route.
Size
50×70 minimum. At 30×40 the Docklands section merges into a smudge and the drawing loses the part most people want to point at.
What to put under it
Official time, not watch time. London is a race with a results page, and the number on it is the one anybody else can verify.
Distance is worth showing as 42.195 rather than what your watch said, for the same reason. Then the date.
Questions people actually ask
- Does the Isle of Dogs section really look like that?
- Yes. The loop through Canary Wharf doubles back on itself repeatedly, and on paper it is the busiest part of the drawing. It is also the part everyone recognises.
- Do I need a map underneath?
- Not necessarily. The river does most of the work — the course follows the Thames closely enough that the shape reads as London without any labels.
- Why does my GPS distance read over 42.195?
- Partly GPS error among tall buildings, which is severe around Canary Wharf, and partly the tangents you did not run. Both add distance and neither subtracts it.
- Can I print it if I ran the virtual race?
- Yes. A virtual race is your route, which is arguably the more personal print — nobody else ran it.
YOURS, FROM A FILE, IN 90 SECONDS
One effort. One sheet of paper.
Bring the file and every choice is yours: treatment, colour, which numbers come along. Museum-grade 250 gsm matte, printed in Denmark, shipped in a tube with a nail taped inside.
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