Even for sighted runners in New York, the marathon course is a challenge beyond sheer mileage. It requires running in thick bunches and maneuvering carefully to the side of the road at water stations, where the pavement is wet and littered with paper cups.
Wheatcroft was using new technology that had not been tested in a race. He understood that many things could go wrong. The metal girders of bridges along the course scrambled the digital compass on his iPhone. He worried about other possible navigational glitches caused by Bluetooth interference.
What if someone stopped in front of him to take a selfie? How would he refill his water bottle? Could he remain on course as the race turned off Fifth Avenue and funneled into Central Park at Mile 24, curling around the reservoir, which had seemed to befuddle his GPS on some test runs?
He had used technology, such as Runkeeper, an app that gave his pace and distance with voice commands. But corrective navigation for visually impaired runners was in its infancy. As Sunday’s race approached, Wheatcroft described himself as excited, nervous, a little fearful.
“It’s a complicated course,…