Not worked that out yet Mike... but I used 2 pace indicators:
1) wearing a heart rate monitor and trying to keep to 120bpm avg.(ie. a good steady low rate - lower the better for long days)
2) using the down timer facility on stopwatch (set to 20mins) Very useful but this technique relies on knowing where the 'milemarks' are. I use features in my written instructions to give me a reasonably accurate idea. (ie. 150m past gate. When timer beeps I then have a rough idea whether I'm up or down on that mile)
based roughly on 16hr days with approx 2hrs of food/footstops
St Bees or Bust!
A Walk in the Park...s