Super Amazing Navigational Techniques for the Navigationaly Challenged and Challengers!
Nav Work 101 - Cardinal Directions and Declination
Nav Work 102 - Crazy Magnets and Stuff
We talked long and hard about Declination, and compass use in the previous thread. Also discussed shooting and taking bearings, so I guess it's time to actually put some of that to use!
There are a few ways to tell distance in the wilderness. One of the "easiest" methods (without the use of a GPS) is with simple pacing. This has been used for thousands of years. For the finer distances you'll use your steps, for longer distances it's often easier to have an idea of your average MPH in the given terrain, and guesstimate your distance base on the time traveled.
Personally, I teach pace based off a 100' baseline. There are a number of reasons I have for doing this, since the majority of distances I may be required to pace off will commonly be well under 1/4 mile, and I typically have other tools to measure things at a longer distance. You could also learn your pace for 100 yards, or even 100 meters. They're all perfectly viable systems and if you go metric there are undeniable strengths in the versatility of the system, it enables to the use of slightly more logical pace beads for example. However most trails aren't measured out in Km, and constantly converting back and forth in your head can be tedious.
Either way Pick a system that you would prefer, stick to it, and learn your pace. This could easily be done on a track or football field for example if you want a longer pace, or using a tape measure / rope to mark out 100'. Be consistent in your system. There are possibilities for error in this method from a thousand directions, so consistency in your training and practice is going to be key to getting remotely reliable results. Try this in all different types of terrain / slopes / vegetation you may be needing this skill, they'll all give you different numbers and you'll start to learn the characteristics of your individual pace.
Generally speaking, your Pace is two Steps. If you lead off with your left foot, you could count Left -> Right (one) -> Left -> Right (two) -> Left -> Right (three)... As you could imagine, this would get rather tedious if you wanted to pace out multiple miles. I would say the average pace for 100' is somewhere around 20. That would put you at 1,056 paces to the mile. I don't know about you but I would rather *not* repeatedly count to 1,056 in my head as I hike. Which system you use is really going to be dependent on what context you'll be needing it in, so I will leave that up to you and do my best to give you the general underlying principals behind it.
You can start to see the major differences when you look at some different units
100ft = 20 Paces
100Yd = 60 Paces
100m = ~65.5 Paces
1/4 Mile = 264 Paces
1/2 Mile - 528 Paces
1 Km = ~655 Paces
1 Mile = 1065 Paces
You could easily make up a chart for whatever your pace comes out to, but there are a few things to keep in mind while doing this. Your accuracy will always come down to consistency, and practice.
- Wear your normal clothing and equipment you'll be using. Your natural stride will change with what you're carrying
- Moderate uphill will shorten your pace
- Moderate downhill will lengthen it
- Steep downhill will shorten it again
- On trail, vs cross country will alter your average
- Obstacles, like climbing through blow downs will obviously screw you up. In these cases it's good to pace between your bearing points and take notes instead of attempting to keep the overall tally in your head
So now we've got your bearing technique, and pacing down. I've had a few questions about how to deal with major obstacles in your path and stay both on bearing, and on pace. Lets go over a couple practical real world methods for both, and then I'll share one of my favorite impractical uber nav-nerd tricks. Most all of these things can be figured out using less steps if you're a fan of Trig. But for those that aren't we'll go the simple way Please pardon the MS Paint graphical wonderness here..
Lets assume you are the Star, traveling on a 0°T (North) bearing along the purple line and have run into a pond that you would rather not cross. This could be because you don't want to swim, or maybe your pace is important and you need an accurate accounting of your distance.
If your pace doesn't matter, but you need to stay on bearing than the simplest method would be to find a target on the opposite shore that is along your bearing, and simply walk around the shore to your new target.
Unfortunately that method doesn't always work, or isn't as easy as it sounds if there isn't a clear and identifiable target on or near your bearing. One potential (although some would say un-ideal) solution for this is some simple flagging tape that will be visible from the other side of the obstacle. Or to be more nature friendly, build some sort of cairn you'll be able to see from the opposite shore. Then you can simple walk the shore, and shoot your a bearing back to that carin until it falls along your back azimuth (the opposite direction of your bearing, or 180° off). Once that's in line, you know you are back on your original path and you can proceed as before.
If your pace is vital, then your options are somewhat more limited. Again, there are a bajillion ways to do this, but this is one of the easiest to actually put into practice without excessive mental work. The main concept is that if your original bearing is not passable, but it would be passable parallel to it on either side, then you simply hop over, and hop back.
In the example above, you are again at the star, the pond is in your way and you want to maintain your pace. It's just four simple steps!
- Take a new bearing 90° off of your original (we're going to make a box here). In this case we are heading north, and will divert to the west, so we will take a bearing of 270°T
- Continue along this bearing until you are beyond the obstacle. Remember the bearing and the distance you diverted!
- Return to your original bearing, walk until you are beyond the obstacle, and add this distance to your cumulative total
- Once clearly past your obstacle, you'll turn the opposite 90° and return the distance you diverted initially to your regain original azimuth.
To be completely honest, most of you guys will not need to rely on pacing often, however in the above circumstance knowing how to do your pace is essential to successfully pulling it off correctly.
The Nav-Nerd example is a straight up geometry put into real world practice. Say we want to figure out the distance across the river, from our location (the star) to the opposite shore (Green Dot)
We're going to solve this dilemma with some similar triangles and some help from the almighty Pythagoras. We're going to call the distance from you to the green dot side A. We'll then walk perpendicular to that bearing for a random distance and call this side B. This distance can theoretically be any distance you want, however round numbers are nice, and something close to your guesstimation of the distance is going to make you more accurate in the long run.
You're going to mark where ever you decide to stop, and shoot a bearing back to the Green Dot. This will complete your first triangle. Remember this bearing! You'll need it in the near future for verification, but you're going to essentially repeat the process again. Doing a perpendicular bearing to side B, to create side a of the second triangle, turn and complete side b until you can shoot a bearing through the previous corner, and back to the original Green Dot.
Now it's just a matter of some "simple" math, assuming you've been keeping track of your distances! Since the two triangles are directly proportional, (if your bearings are good) you can safely assume that sides A/B = a/b
To break that down a bit more, we're looking for length A. I'll make up some numbers for the others so we can work through the math. Lets assume the following:
From that we can say that A/100 = 35/42
A/100 = 0.83333...
We can get into using Trig to tell heights of cliffs/trees if you guys are interested in that, but I think I'll end this thread here for the time being. Apologies for the massive delay between this one and the last, been a busy year to say the least!
Next one we'll get into using Topo maps and how to shoot/take bearings with your compass on them!
Questions / Comments / Concerns / Critiques?? (I typed this one up while I was at work, shhhhhh don't tell!). I appreciate any sort of feedback, it's good to know if these things are helpful to anyone in the slightest. If they are then I'll keep them up
Cheers! Keep Calm Hike On!