birkhead mountains virtual orienteering

One of my 2023 resolutions is to get better at orienteering. I tend to gravitate to longer courses,  but what I've learned is that endurance and speed can compensate only so much for navigational ineptitude.

Longer courses around here are 4-hour score-Os hosted each year by BOK. Last year's score-O was in our backyard at Eno River State Park. I suffered a few blunders that kept me from clearing it, but it was good practice. And I definitely needed more of it.

I'm happy to now have access to virtual courses using the Usynligo app. I recently got to try this out at Birkhead Mountains Wilderness on a 4-hour score-O originally held in 2021, which I missed due to DALTAR.

Unlike an actual score-O where one has less than an hour to study the map and prepare a route, I had all the time I could want. I avoided the temptation to look at previous routes to give myself a chance to come up with my own.

I moved the start/finish to just upstream from the Tot Hill Farm public access (star) and drew out a clockwise route (red) of about 20 km to clear the course. I then drew out a longer path (yellow) with catching features, handrails and attack points that might help me stay oriented.

Next step was to make a physical copy of the map. Thanks to Dave the course designer, I had access to the 1:10000 map pages, which I printed, cut up and taped together. I used packaging tape to 'laminate' the map and attached a red thread to mark a direct line of travel between controls.

Dave warned me there'd be some limitations with the app on this course as large chunks weren't georeferenced. He set up a nearby virtual course for me at Eno to use as a test leading up to Birkhead. I hoped to troubleshoot the app beforehand.

One thing to sort out was control radius size. The app's default setting is 15 meters, meaning the virtual control gets "punched" when the phone is within 15 meters. For reference, control symbols on orienteering maps such as Birkhead have a radius of about 40 meters.

On one hand, I thought 15 meters would be too small of a target to hit given map misalignment, not to mention a phone's GPS accuracy being what it is. On the other hand, how sporting is a larger radius? As shown, I've missed controls within 40 meters.

I settled on a radius of 20 meters with minimum GPS accuracy of 10 meters meaning that I'd have to cross well within the red circle of a control symbol on the map to score. At that point, I'd hopefully hear an alert on my phone for any georeferenced control.

I wouldn't worry about the app registering my arrival at non-georeferenced controls. I'd instead run into the control radius preferably around the feature itself and later upload the track to see how I did. In the animated example above, I wouldn't score.

One important consideration is hunting in Birkhead Wilderness. I thought better of wearing my deer costume and also planned to start the course early on Sunday morning (per NC hunting regulations, no gunfire from 0930-1230 on Sundays).

Dad wanted to join me Jan. 29th down in Birkhead for an adventure. He would get out for a couple hours exploring the "rock garden" while I tested myself on the score-O course. We drove the '76 VW camper down to Tot Hill Farm and got started at 0830.

The weather was overcast and cool, perfect conditions. Still, I found myself moving slower than expected through the Gray Owl section of the map. It seemed to take me a while to hit a groove. There was a long delay with app alerts, which was exasperating. 

It took me over an hour to collect the first nine controls along my route leading into the rock garden. My biggest mistake was at #551, which should've been so easy! I was happy to bump into dad here before heading deeper into the wilderness.

Next up was a kilometer-long traverse up and over Cedar Rock Mountain to #642, the first of many non-georeferenced controls. I didn't expect to hear an alert so wasn't surprised by silence when I arrived at what I was sure was the right feature.

It was initially difficult for me to later project my track onto the orienteering map to decide if I got near enough to this and a few other controls. But thanks to Brian, my track is now up on routegadget. Turns out I was way off on #642!

I made the 13th control #652 by two hours. I was getting intermittent app alerts, which messed with my head. Being so hyper-focused on navigation meant I had fallen behind on nutrition and hydration. Clearing the course was no longer an option.

At #446 I made a quick decision to deviate from my route and skip #449 in favor of higher scoring controls. My target was #856 by three hours. I missed the fence line, lost more time. With no alert at #856 I was getting fed up with ghost flags.

I foolishly stopped to tag a few more controls on my otherwise hasty retreat. I tried to tiptoe around some private inholdings, but mistakenly crossed through one short section before a brutal cross country climb back to Birkhead Mountain Trail.

My legs were spent, but I brought it home in 4:11 having optimistically tagged 23 out of 28 controls. This was a humbling workout. I much prefer real to virtual orienteering, but am thankful to Dave for making this training resource available.