Meanwhile, a cryptic email from Gavin Williams directed me to the results for the Race the Sun event on the Isle of Man.
A team going by the name “Dark Peak & Manx Fell Runers” (sic) won the race in a time of 10:14:54, 2 and a half hours ahead of the second placed team. Looking at the race website it appears that the team must start at sunrise and complete the 100 mile coastal path before sunset, no doubt Gavin could tell us much more.