Our Navigation Plan
Subtitle: Arc of Attrition 2019 Navigation
Marcus and Agata need a solution to a simple to understand problem.
We have state of the Art GPS Watches that have a maximum battery life, within an activity of 18 hours.
However our Race will last upto 36 hours.
The need to navigate any Race in this case a 36 hour, non stop Running Race, depends on signage. In the best case the course is marked with signs every few hundred metres. This makes navigation trivial: if after a few hundred metres you don't find the next sign, you have taken a wrong turn.
Unfortunately the race we undertake has no race specific markings at all. The instruction to "follow the Cornish Coastal Path" signage might sound simple. However:
- Even in daylight, signs are several km apart
- In the dark it is easy to miss a sign
- Once you take the wrong direction you are basically screwed
- Garmin watches can load a .gpx route tracklog. This is a detailed path of a previous runner. But even this is far from foolproof.
Especially in the dark you can take a wrong turn, and as we found out in 2018, backtracking can take over 20 minutes, and do this only a few times and you will be out of the race (missed checkpoint cutoff)
So a tracklog on its own is not typically enough to follow, especially not in hostile weather conditions when you have been running for tens of hours.
We need a better solution ...
What Doesn't Work
Your Smartphone with offline maps pre-loaded and a decent application (e.g. Ordinance Survey) would be a far better navigational aid.
The issue is that it is not wrist based. And, for the tens if not hundreds of times when you need to make a decision, you would need to stop, take off your gloves, take out the Smartphone, unlock it, check position. And make sure the phone does not get wet ... It just does not work. It can only be used for that the exceptional case where nothing else works. And in this race every second counts, because most fail to complete the course in the time allotted.
Advances in Garmin
Starting with the Garmin Fenix 5X and now all members of the Fenix 5 Plus Family (S, Regular and X) every watch contains a detailed basemap.
This actually makes a vitally important difference
With your track log loaded, your course is shown on top of a detailed map that already shows walking/ running paths, and geographic features. So when you come to a decision point, perhaps a fork in the road, you should be able to see the possibilities and your .GPX route laid on top.
So now you can more easily see which way you should be going.
It actually makes all the difference in the world
Ultratrac Does not Fix the 36 hour time requirement
Garmin watches have an UltraTrac mode that decreases the GPS sensitivity, enabling gains in battery life. Unfortunately if you turn this on you will more or less get instantly get lost. The GPS position is accurate to about 1 minute, so when you get to one of the hundreds of turns, especially at night, you only need to go wrong once, and recovery can take not just minutes but tens of minutes. Do this a couple of times and you are basically screwed, you will not reach the next checkpoint in time.
3 Watch Solution
Here are the lifetimes of the watches, and lower down the Charge timings. In regular GPS mode the Fenix 5 Plus can last at best 18 hours and probably less. It actually seems to depend most on backlight settings and if the map is being displayed (hint, make it display for seconds on wrist motion only)
Our Cunning Plan
Marcus is running with the Garmin 935, with just a tracklog and no basemap, which I hope will last to the halfway point. At which time we'll spend 30 minutes eating, changing clothes and critically charging my watch.
Meanwhile Agata will start the race using the Garmin Fenix 5 Plus with the detailed basemap. When that runs out of juice she will start using the smaller Garmin Fenix 5S Plus and start
charging her Fenix 5 Plus using the 170 gram Anker 6700 mAh Power Bank. She will do this on the fly whilst running. To fully charge should take less than 3 hours, comfortably less than the 11 hour lifetime of the Fenix 5S Plus.
In fact once the 5 Plus is re-charged, she can use it again, then I can take the Fenix 5S Plus and use it, and put my Garmin 935 on charge.
Will It Work?
We have tested the 3 watch charge and swap scenario, but only for a few hours. Only time will tell if it works in real life. And that time is pretty soon.!