Navigation Skills 10 – Better Bearings
By Dave Roberts
on February 8, 2015 5/5 (2)
Navigation Skills 10 – Better Bearings
We’ve already mentioned the basics of taking a bearing, but you’ll need to master a few more skills in order to be able to follow it accurately.
Take your bearing accurately. Practice, practice and practice. You’ll be very unlikely to take both the perfect bearing and follow it perfectly, so consider that for just a 1° error, you’ll be off track by 1 in 60. In other words, travel 60 metres, and you’ll be 1 metre off. 600m and you’ll be 10m off your target. That’s for every 1° error! Remember that you’ll struggle to get a bearing this accurate – so if you’re following a bearing over 600m, always assume you’ll be 20-50m off target. That’s if you can take a good bearing!
Shorten the distance. There’s a really easy way to increase your chances. Keep the distances walked on the bearing as short as possible. You’ll be more accurate over 5 200m bearings than 1 over 1000m as you’ll be nearer your target every time, and therefore more likely to find it.
Don’t use a bearing at all. If there’s a better technique to be used, use it. More often than not, there’s an easier and more accurate technique you can use – but more about that in our next article.
Follow Your Bearing More Accurately.
Keeping to a bearing is hard, and while practice can help, you can also increase your accuracy during the legs.
Leapfrogging. This basically means that one of your party walks along the bearing, and those that remain take a bearing onto that person to see how accurately they’ve followed it. They’re then instructed to move left or right. The second navigator then ‘leapfrogs’ the first, and the process is repeated. You can also use this technique if you need to cross a feature that makes following a bearing difficult, perhaps there’s an incised river or ravine.
Back Bearings. You can use these to check back to your starting point – perhaps you set off from a rock that’s still visible, or a fence post.
So long as you can take a regular bearing, backbearings are easy! Simply rotate yourself so that the white end of the needle is aligned with the orienting arrow. The needle should be pointing back at whatever landmark you left.
So bearing that in mind (groan!), if the feature you’re heading for doesn’t provide a large target, you’ll still need to use some tricks to help you. You’ll find that it’s often best to use these wherever possible.
Techniques for hitting your target.
Aiming Off is a rather a crude but effective way of increasing your chance of hitting a target. If aiming for a stream junction, you may just miss it on your bearing and you won’t know if you’ve gone too far in one direction or the other. It’s better therefore to put an error into your bearing and aim-off up or down stream of your junction. You then know which way to follow the stream in order to get to your target.
In this example, we need to follow the northernmost stream, and by aiming off, we know for certain that we’ve followed the correct one. Had we followed the first stream, we’d be far from where we’d like to be.
Attack Points are large prominent features that you can use to bring you closer to a smaller, less prominent feature that would otherwise be difficult to pinpoint accurately. You may need to find the stream junction above as you’re using it as an attack point for the bothy. You know that the bothy is 200m on a bearing of 45º from the stream junction which is much easier than trying to find it by taking a direct bearing from your starting point.
Here, we’re trying to get to the small tarn to meet the rest of the party for a wild camp. We could easily miss the tarn by taking a direct bearing, but there’s no way we’re going to miss Llyn yr Adar. We’d probably walk along the shore for a timed distance before setting off on a direct bearing for the tarn.
Avoiding Obstacles by Boxing Off.
You may also need to avoid obstacles on your bearing– you can box around an obstacle, e.g. a small lake – 1 – you stop on the bearing and follow a new bearing 90° to the original (roughly south in this instance), for a fixed distance that allows you to clear the obstacle. Then follow the original bearing for fixed distance in order to clear the obstacle (2). Take a bearing 90° in the opposite direction to the first (3), but for the same distance. Finally continue on your original bearing remembering that distance 2 should be counted under the leg total, while legs 1 and 3 should not.
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siDave Roberts founded Walk Eryri in 2004, with the aim of providing routes that are off the beaten track. Walk Eryri is now part of Mud and Routes which continues to provide more off beat routes and walks in Snowdonia and beyond. Dave has been exploring the hills of Eryri for over thirty years, and is a qualified Mountain Leader. Dave also established Walk up Snowdon, Walk up Scafell Pike and Walk up Ben Nevis just to mention a few.