Yesterday, I participated in the 123rd running of the Boston Marathon. Not as a runner mind you, but as a volunteer; specifically an amateur radio communications volunteer. Amateur radio is one of the three radio systems going during the Marathon, operating along aside public safety radios that are interoperable for the event and the commercial DMR radios that the Boston Athletic Association (BAA), the race organizers, have rented for the duration of the event. There are various roles amateurs play at the Marathon and it is divided into four segments, Start, Course, Finish and Transport. Start and Finish work obviously the start and finish line. Course, which was the segment I was assigned to, is split among the hydration and medical stations along the course and Transport works the sweep buses to pick up runners who have dropped out. Course and Finish also have Net Control Operation Centers that serve as the focal point of relaying operations for their respective segments. T