In 2005, the Marathon was my first official duty in St John Ambulance. I've been back every year since, so today was my 7th time. From 2005-2009 I was out with my local unit, 8 or 9 miles into the course. We'd stay at the same spot all morning, and wait for all the runners to go past. In 2010 I went out with the Cycle Response Unit, and I started out at the 13 mile mark (near Tower Bridge). I roamed around central London, and this gave me a chance to see a bit more of the route.
Today I was out with the CRU again, and this time I cycled down to Greenwich (with my partner) to the start line. From a logistical point of view, it was interesting to see how that all worked, e.g. the "cloakrooms" for bags were actually lorries, and we saw them driving off towards the finish line as soon as the runners started. We then followed the first 25 miles of the route, so that gave me a much better idea of how it all fits together.
Overall, I cycled 42 miles. I had to be up at 04:30, so I feel quite tired now. Anyway, it was a good day out, and I was able to make myself useful.