All the term ‘navigation skills’ really means, is the ability to look at a map, plan a route and follow it. A good navigator will break these bigger tasks into smaller objectives. They will then create a solid strategy for how to approach these objectives methodically and work through them. Creating a good navigation strategy comes down to the 4 Ds of Navigation. Most commonly, these stand for distance, direction, description and duration. Read on for how to use these to create a navigation strategy which allows you to confidently navigate anywhere in the world.
The Four Ds of Navigation
Many hikers use the 4 Ds of Navigation as a memory rule for the things they need to think about when navigating. When used together, distance, direction, description and duration allow you to form a comprehensive strategy for following your route. Using these aspects will allow you to plan and follow routes using just a map. However, more detailed navigation using a compass will also follow these basic principles. More about compasses and their use in navigation in the next lesson!
The first thing to consider when starting to plan a walk is its distance. Measure the distance of your route using a map. You can check this earlier lesson which explains map scales and how to measure distances on the map. Always plan a hike which is within your abilities. Deciding on a distance is a good way to do that! However, it is important to take into account that elevation gain and complexity of the terrain affect the overall difficulty of the walk.
In addition to measuring the overall distance of your walk, dividing it into shorter, easier to track distances, is an important way to structure your progress. Most people will have an overall idea of their route in their mind before starting the walk. This can be divided into shorter navigation legs/stages used to identify points along the route. The length of these legs can vary depending on the complexity of the terrain, your experience and the visibility.
The most important thing is to keep them manageable for yourself and appropriate for the conditions! If you are still learning, or if the conditions are very challenging, your navigation legs might be just a hundred meters. If you are confident that you can keep track of the route easily, they might be several kilometres. (For example, when you can see the landmark you are aiming for. Or in situations where you are following a well-defined path and there are no junctions).
Knowing the expected distance between your starting point and the next landmark along your route will help you to accurately aim for it. For example, if you are aware that you need to cross a fence in 500m or turn onto a different path in 800m, it will allow you to look out for these features before you can see them. If you know how far your next landmark is, this works as a way make sure you won’t miss it! Therefore, if you know that your next landmark, such as a building or a wall, is a certain distance away. You can then anticipate it. But also know that you may have missed it if you have walked a longer distance, and there is still no sign of it.
(There are some limitations to this. It is important to double check that you initially measured the distance correctly, tracked it correctly, and chose a landmark that will certainly still be there, i.e. not something which changes with time).
Ensure you know which direction you need to walk to. This can be done by correctly orientating your map to the ground, as was discussed in the last lesson. Or by using a navigational aid, like a compass, which will be introduced in next week’s navigation lesson. It is important to periodically check your progress and location on the map by re-orientating the map to the ground. This will allow you to check that you are still progressing in the right direction. Without this it is easy to get complacent with your progress and ignore warning signs which tell you that you have turned away from your intended route.
Description means matching what you see on the map with what you expect to see on the ground. Once you know which direction you are walking to, and for how long, make a plan of what you expect to see during that distance! For example, if the next leg of your walk is 500m along the path you are already on. (And you have checked that you are facing the right direction on the path by orientating your map.) Then you can create a list of details you expect to see within that distance. Look out for clear and easy-to-spot landmarks, which haven’t changed with time. As you walk, tick these features off the list in your mind as you pass them. This will allow you to constantly check that you are still on the right course. And helps you to keep track of your location on the map.
The last of the 4 Ds of Navigation is duration. Now this is a slightly more intricate skill and will require some adjustment to your personal walking speed. Essentially walking a set distance, on a specific type of terrain, will take a certain time depending on your personal walking speed. Therefore, by looking at your map and knowing the distance you will be walking, you will be able to know the approximate time it should take you to reach that destination. This can be a helpful way to make sure you do not miss the landmark you are aiming for. This will allow you to keep double checking your navigation and make sure you never get into trouble by veering too far off your intended course.
Your pace dedicates the distance you can travel in a certain time. As a short(ish) woman, I find that depending on the terrain I usually travel at between 3km/h and 4km/h. Any faster than that usually means significantly pushing myself. And any less than that requires the terrain to be very difficult to travel on! Therefore, if we look at the pacing card below, we can see that traveling the distance of 100m at the pace of 4km/h will take me 1.5mins. 500m at the same pace will take me 7.5mins and 1km will take 15mins. Equally, this means that I can calculate roughly how long a whole walk will take me. If I have planned to walk the distance of 12km, at a constant pace of 4km/h, this will take me roughly 3 hours. (Plus any breaks I might want to take!)
You will quickly learn your normal pace by keeping track how long it takes you to walk certain distances. Or by using a sports watch or your smartphone to track it for you!
However, as I mentioned earlier, this general rule is affected by elevation gain and by the complexity of the terrain. The general rule to account for the effect of elevation on your timings is called the Naismith’s rule. It states that for every contour on the map (= for every 10m of elevation gain), you need to add a minute to your timings. For elevation loss, this is more complicated and will depend on how easy the terrain is to descent! A steep descent can add roughly the same amount of time as ascending the same terrain. The time it takes to descent is often underestimated by inexperienced hikers. And this may add an unexpected chunk of time to their day.
Example: You are walking a distance of 2km and ascending 600m in that distance at your normal pace of 4km/h. This distance would take you 30mins on a flat surface. Add to that 600 meters of elevation, which means that you will cross 60 individual 10m contours on the map. So, you need to add an extra 60 minutes to the estimated time! Therefore, it will actually take you 1.5 hours to reach the top. Additionally, it is important to account for any breaks you need to take. Personally, I assume the need to stop for a breather a few times during this amount of elevation gain. So, I would add approximately 15mins to allow for this. This would mean the walk will take 1 hour and 45mins.
You can perform these calculations for any pace (km/h) depending on the terrain, visibility and your (or your group’s!) normal walking speed. Knowing the duration of either your whole walk, or of the navigation leg you are on, is an important way to plan your route. And to keep track of your navigation along the way.
The 4 Ds of Navigation plus one?
The 4 Ds of Navigation is nowadays often supplemented with extra detail. Many instructors like to include a fifth D, which usually denotes dangers. Are there any hazards on your route which you should be aware of? These could be things like sudden drops, river crossings or loose scree. What can you do to mitigate the risks? Will these hazards cause you to deviate from your planned route? Hiking, especially in mountainous environments, has some inherent risks. Therefore, it is very important to learn to continuously assess these as you walk. Ideally, be aware of possible risks before you get to them in order to be prepared to make appropriate decisions.
Let me know what you thought about this introduction to creating a navigation strategy using the 4 Ds of Navigation by leaving a comment below! To follow my outdoor adventures and get more useful outdoor content, have a look at my Instagram and Pinterest accounts.