Infernal devices

Text and photosTerry Cornall

Infernal devices

I do like a nice GPS receiver with displayable map. I also despise having to recharge them all the time. I spend a bit of time now and then working on a design for an e-paper based device with a 7" screen.

54 | Bushwalk October 2024

the resources possible to reach out for help. InReach appears to be very good, but having the PLB backup at the cost of 250 grams was worth it to me. At least I left my Garmin Dakota 20 handheld behind, lovely little thing that it is, it's made redundant by the Fenix watch.

We're da Hekawe: Navigation and pathfinding

According to the writings of the legendary Korean military scholar General Soon Sing Song, she says, "Navigation is the art of knowing where you are, knowing where your destination is and then the path needed, according to the roads, the terrain, the weather and the deployment of the enemy, of getting from one to the other. Pathfinding, however, is the art of knowing which rock to stand on next". In our case the enemy was the blackberries and trackless bush. The weather didn't really play a part in navigation but in cases of flooding or high winds or lightning, it would have been best to avoid low and high grounds. Terrain is always important. Best to avoid steep bits if possible. Mostly we chose to use tracks and roads as advised by Chapman's notes, but sometimes we chose to use alternatives that would bypass choked gullies, ridges made difficult by regrowth, or just plain boring bits. 'Interesting' bits were treated with caution too...

A map and compass can go a long way to help with the navigation, i.e. the strategy, and certainly having a compass bearing helps to guide the pathfinding, i.e. the tactics needed to carry out the navigation plan.

All of this does require you to know where you started from and where you actually are at a given time. Skilled users of map and compass can, with keen observation of the landscape (and sometimes signposts) get a long way in working their position out. However, a GPS receiver with a map (or the ability to give map coordinates that can be referred to a paper map) is a great boon to the modern traveler in the bush. Used properly, the GPS can tell you where you are with great accuracy and guide you in both the navigation and pathfinding. We relied on the maps and notes for working out how to get from A to B and the GPS receivers to make sure we stayed (when sensible) on

our planned path and to anticipate turnoffs. We also used our discretion to re-plan the path on the fly if it proved to be infeasible due to lost path, blackberries or thick scrub. Mostly we were following an obvious path like a road or a bush track or a river and that made pathfinding pretty easy, but now and then the path was inscrutable and we just had to pursue a general heading or follow terrain features like ridges or rivers. It wasn't hard but it did take some thought. It really helps too if

Stay on target...

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maps as CS3. Turn right and follow the vehicle track..." do require some thought. Is the vehicle track we are meant to follow the original one or the new one? Did give us pause, but wasn't hard to get right, especially by referring to the printed maps and various marked courses on various GPS devices.

GPS device said we were off course and urged us to 'go into the woods' but they were gnarly and tangled and monsters lurked therein and we could see a better, clearer way to go, even if there was no beaten path. This happened on the Long Hill course to The Crinoline when the clear path we were following entered a clearing and no obvious exit path could be seen. It was made worse by various bits of pink tape indicating that yes, someone had been here before, but still no real path was obvious. However it was clear to Gordon at least that we should stay out near the 'rim', where it was clearer of scrub and bordered by rocks shielding us from a steep drop off, rather than follow the marked course religiously. This worked, so if it’s possible to do so without messing up the navigation, your pathfinding strategy should be: 'Don't go into the deep dark woods'. In this case it was clear from the maps that following the rim would get us to where we needed to go, and Gordon had a memory from long ago about all this, so we went with his plan and hit the campsite perfectly with minimum bush-bashing. Sometimes the marked course is just wrong, whether because it was entered into the GPS device improperly or too coarsely or because the maps were wrong or because some numpty had decided to make a new path and not enough people had used it because it was silly.

Not on this trip, but a bitter memory from the first GPS device I ever carried (and never again) was that I could NOT find the menu item to navigate back along the route we'd recorded on the way out. This was in bitter cold in the snow with a rapidly draining battery and I wasted (what felt like) half an hour scrolling through

menus and settings. Turns out that that setting was only available if you landed on the navigation actions page from a particular starting point, otherwise it was invisible. Aaaaargh! Nested menus with disappearing options are the WORST idea we software people have ever come up with! Take home message is 'Practise with the GPS before trusting your life to it'. (We made it out alive, BTW)

Maps on some GPS devices not detailed enough. Yeah, like the TopoActive Australia map on my phone used by the Garmin Explore app. Very uncluttered by silly irrelevant details like medium-sized creeks, minor track names, huts etc. Aargh! I was standing right next to Lankey Plains hut and it didn't show on the map at a reasonable level of zoom. When I zoomed right into where I knew it was, suddenly it popped up as a tiny weeny icon and text. How ridiculous! I had to know exactly where it was in order to find it and look at the size of the text and icon compared to the dashed line of the track.

I think we are on track... Let me check the map...

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Yay! We made it! Now where's that ambulance?