[1] Hi Brian Porter. I met you at the Course Measurement Upgrade Seminar in Blackpool last year, good to see you on here spreading the gospel.
Re-the accuracy of garmins, it is worth adding that much depends on the prevailing conditions. In optimum conditions garmins are very good. I have measured a 7 mile circuit by calibrated bike on the flat expanse between Southport and Ormskirk which is devoid of trees and buildings. Cycled the circuit this morning three times under a clear blue sky and garmin was correct within 15 yards every time – so much better than 99% accurate.
But I have measured a 3.86 mile circuit by calibrated bike which includes trails through pinewoods – eleven runs have produced garmin distance of 3.87 (2), 3.88 (4), 3.89 (3) and 3.90 (2). So 99% garmin accuracy is about right in poorer conditions.
So I guess that runners should not trust their garmins if a course takes in deep canyons, forests and skyscrapers. In general of course, garmins tend to measure over distance and for many reasons. Not least that runners may line up back from the start line and then not run the shortest possible route, especially if they are in the middle of the field.
PS: Many thanks to Old Poster for explaining the grounding of the ship off Blackpool last year.
