Part I

Before being able to take a compass bearing it is essential to understand the relationship between True North, Grid North and Magnetic North. (Part II, walking on a compass bearing, will follow next month).

The Three Norths

Grid North

Grid North is the navigational term for the northward projection of the north-south gridlines on a map. In Ireland it lies to the east of both True and Magnetic North.

True North

True or Geographic North is aligned with the Earth’s axis and points to the geographic North Pole, the axis on which the Earth is spinning. In Ireland it lies west of Grid North and east of Magnetic North.

Magnetic North

Magnetic North is defined as the direction toward which the north-seeking, (red) arrow of a compass points.  Magnetic North is the northern pole of the Earth’s magnetic field and it deviates from True North over time because the earth’s magnetic poles are not fixed in relation to its axis. The current magnetic north pole is located in the Arctic Islands of Canada and is moving very slowly eastwards. In Ireland it currently lies west of both Grid North and True North.

The relative positions of Grid, True and Magnetic North will vary, depending on where you are in the world.

For the purposes of mountain navigation in Ireland and the UK, True North can be ignored.


Magnetic Variation

Magnetic variation is the difference in angle (in degrees), between Magnetic North and Grid North. It varies from place to place, and with time.

In those countries that do not use a grid system, magnetic variation is the difference in angle between Magnetic North and True North.

When taking a bearing from the map, we initially align the compass with the north-south grid lines, or Grid North. However, the red end of the compass needle is pointing to Magnetic North, and we must make a small adjustment to the bearing for this.

Information on the magnetic variation for a particular area can be found in the margins of the map. To calculate the Magnetic Variation we need three pieces of information from the map. 1) Year of map update. 2) The rate of decrease (or increase) of magnetic variation. 3) The current year.

From this information it is possible to calculate the adjustment applied to the compass bearing.

At the present time in Ireland the magnetic variation should be added when taking a bearing from the map to follow on the ground.

In The Wicklow mountains the current magnetic variation (2017) is 4.0 °


Taking a Bearing

  1. Place the compass on the map so that one of the long lines on the base plate, (or the compass edge, though this is less accurate), is touching both your starting point and target point.  Ensure that the ‘direction of travel arrow’ is pointing towards your target point.     (diagram 1)
  2. Hold the compass firmly on the map and rotate the compass housing until the orienting lines in the base of the housing are lined up with, (running parallel to), the north-south grid lines on the map; and the orienting arrow is pointing north.  (diagram 2)
  3. Take the compass off the map and read the bearing at the index line on the compass housing. This is the Grid Bearing.  (diagram 3)                                                                                                                                                                                                    
  4. Calculate the magnetic variation for your location and add or subtract this from the grid bearing. Adjust the bearing at the index line accordingly. This is the Magnetic Bearing.
  5. Hold the compass in front of you with the direction of travel arrow pointing directly away from you. Turn your whole body until the north end of the needle lines up with the orienting arrow (put red in the shed). The direction of travel arrow is now pointing you towards your target.

Take a compass bearing


Take a compass bearing












Take a compass bearing

To learn more about mountain navigation, or to join one of our very popular Mountain Skills courses, go to:

Mountain Courses



Many of us have an altimeter as an integral part of our mountain watches, but how many of us know the skills of navigating with an altimeter?

Here are 5 tips on how to use an altimeter as a navigation tool.

Before we begin however, a note of caution, altimeter watches rely on barometric pressure to calculate altitude and as the barometric pressure fluctuates so does the altitude reading, and this can lead to serious errors if not addressed.

It is important to re-calibrate the altimeter regularly by re-setting it to the correct reading when a known altitude is reached, such as a summit, col or spot height. Read the height from the map, and adjust the altimeter accordingly. This is particularly important in areas where the pressure may change rapidly as weather systems track across the globe, for example over Ireland and the British Isles. Here adjustments should be made every couple of hours, as and when the opportunity presents itself.


  • Knowing how high you are (absolute altitude)

Knowing how high you are (your altitude) and how far you still have to climb is a great way of monitoring your progress. This is particularly helpful on a long uniform slope with little in the way of landmarks, or when visibility is reduced as clouds descend or when night falls.

In poor visibility, reading off the altitude can indicate if you are at the summit of your mountain, or merely a lower, subsidiary top.


  • Ascent rate

Checking your ascent rate is a great way of monitoring your progress. By checking both your increasing altitude and the time taken you can estimate your arrival time at the summit.

For example, if you have a 1,000 metre climb to undertake, and you have completed the first 200 metres of ascent in 30 minutes, then it should take you another 2 hours (4 x 30 mins) to reach the summit. You can check your progress against the estimated arrival time, and if all is going well, reach the summit. Equally, you can re-assess your plans or turn back if you are falling well behind the clock.


  • Descending a slope

Navigating with an altimeter (1) If you are descending a slope, perhaps in poor visibility, and you are required to make a change of direction to avoid steep and craggy ground, check the map for the height at which you need to turn off and when your altimeter reads that height, you can make the necessary change. (In the example below this is at the 790m contour).

This technique would work equally well if you were ascending a slope and needed to change direction.




  • Traversing (Contouring)

Maintaining the same height as you traverse around a slope, (following a contour line), can be notoriously difficult in bad weather. There is a strong tendency to lose height as you go, and drop down the slope.

Checking that the altitude reading on your watch remains constant allows you to maintain your height and traverse the slope without any problems.


  • Relocation (Aspect of Slope)

Navigating with an altimeterIn a previous blog on relocation techniques, I explained how to use your compass to determine the aspect (direction) of slope and thereby determine what side of the hill you were on:

Feb 2017 Relocation Techniques in Navigation)

This navigational technique can be combined with an altimeter reading to determine your exact location on that slope. In the example below the altimeter reads 600 metres, which places you at the red cross on the map.



Used in combination with other navigation skills, and your map and compass, an altimeter can be a valuable addition to your navigation toolbox.

It’s a cliché to say we have become reliant on technology, and we certainly need a map and compass, and perhaps a GPS system, to find our way around unfamiliar hills.

But how did our ancestors find their way around, and what natural features did they use to navigate across the land in times gone by?

Here are 5 ways in which our forebears may have navigated around the landscape; and though we don’t suggest you leave your map and compass at home, it might be fun to try these out sometime, and see if you can navigate like the ancients!

Navigate by the Sun

We all know the sun rises in the east, but in reality, due to the complicated relationship between the Earth and the Sun, this only happens on the equinoxes, in March and September. In the middle of June it will rise in the northeast, and in December in the southeast.

However, it is possible to use the sun to determine the cardinal points (North, South, East, West) by using a ‘shadow stick’. To do this you need a stick around a metre long a handful of pebbles and a sunny day.

Push the stick upright into the ground and mark the end of its shadow with a pebble, now hang around. Every 15 minutes or so mark the end of the sticks shadow with a pebble, and after an hour a distinct line of pebbles will become apparent. The first position of the shadow is the western end of the line, and this line is aligned west to east, allowing you to determine the cardinal points for East and West, and those at right angles to that line, North and South.


Navigate by the Moon

It is possible, when in the northern hemisphere, to find south by observing the Moon. Look up at the Moon when it is waxing or waning, (this does not work when there is a full Moon), and draw an imaginary line between the ‘horns’ of the crescent of the Moon. Continue that line down to the horizon, either by eye or by holding a straight object up to it.

The position on the horizon where this line falls is South.


Navigate by the stars

The details of how our ancestors navigated by the stars may seem complex to us now, but perhaps the easiest piece of stellar navigation is this method of locating North.

Natural navigation - using the stars

Many of us in the northern hemisphere can recognise the constellation Ursa Major, or the Plough, it’s the one with the distinct saucepan outline.

By locating the outer edge of the ‘pan’ we can draw a straight line, about 5 times the distance between these outer stars, and here we will find Polaris aka the North Star.

The North Star sits directly above the North Pole on Earth, and so enables us to find the direction of North.


Navigate by using plants

Plants will always grow towards the sun, and a tree will always have heavier and more luxuriant growth on its southern side rather than its northern side. To see this effectively you need to find an isolated tree growing alone, in a wood the trees are crowded for space and this effect is overshadowed by the need to compete with each other.

Certain lichens and mosses prefer sun to shade, and can often be seen growing on the southern side of large tree trunks, this can be quite reliable when seen on a number of trees growing together.


Navigate by the wind

The prevailing wind, (the direction the wind predominantly blows in), can be determined for your location. In Ireland the winds are generally westerlies, and in exposed areas trees will be ‘raked’ by the wind and will grow bent and downwind. By observing the shapes of these trees it is possible to estimate where West is.

The wind does not change its direction a great deal during the course of a day, unless a frontal system passes though, and this is usually easy to spot. So it could be possible to navigate using the feel of the wind on your face, or the direction it is blowing the grass and other vegetation. However, in hilly areas the wind can swirl around the peaks and saddles, so this may not be so reliable in the mountains.


Russ Mills runs Mountaintrails, a guided hiking and navigation training business based in Dublin, Ireland.

You may wish to learn to navigate using the more familiar methods of map and compass. If so, check out the navigation courses on our website: Mountaintrails Navigation Courses

One of the most important navigation skills is being able to relocate yourself when you have become ‘lost’ or more correctly, ‘temporarily misplaced’. Having the relocation techniques to deal with such a situation is a key element in being a competent navigator.

Firstly, do not panic. Stay calm and stay where you are.

Many people, on realising they are misplaced, will press on more quickly, or walk in any direction in the hope of finding something they recognise, thus making the problem worse.

Have something to eat and drink, this will both give you time to calm down and increase your blood sugar to help you think.

Gather All Available information

What can you see around you? Are any features in view, such as a forest edge or a stream, and what is the shape of the terrain around you, which way is the ground sloping?

How far have you walked since your last known position, (the location where you were last certain of your position). How long did it take you? What distinctive features did you pass, such as a path junction, knoll or forest edge?

See if you can locate any of these features on your map, and use the information to narrow down the possibilities.

Aspect of Slope

If the terrain you are on is sloping it is possible to use this important technique to help you find your position. Use your compass to take a bearing directly down the line of the slope, that is the line that a rolling ball might take, adjust for magnetic variation, and then search the map for slopes with that aspect.

Mountain Navigation - Aspect of slope

In the example above, if we know we are somewhere in the vicinity of hill 668, and we take a bearing down the slope of 198°, then we can eliminate all slopes that do not have that aspect.

With our bearing set on the compass, we can line up the orienting lines in the compass housing with the north-south grid lines on the map. By moving the compass around the map we can locate the slope(s) where the long edge of the baseplate is pointing directly down slope, (and is at right angles to the contours).

We can now locate ourselves somewhere on the southwest slope of hill 668.

Back Bearings

If you have been walking on a bearing, and the indications are that it was incorrect, then it is still possible to return to your last known position.

Instead of walking with the red end of the compass needle aligned with the orienting arrow, (keeping red in the shed), turn yourself through 180° and align the white end of the compass needle with the orienting arrow, (put white in the shed).

Following this bearing and remembering the paces, or time it took, you can return you to your previously known position. This will only work if you did not stray wildly off the original bearing, or wander around the hill hoping to see something you recognised.


Resection can be a time consuming process. It also relies on the fact that you can see far enough to identify two, and preferably three, major features that are also on the map such as hill tops or stream junctions.

It could be argued that if you can identify these features then you are not misplaced! However, under certain circumstances it can be a useful technique. If you are somewhere along a long, featureless ridge for example, and need to pinpoint your position more accurately.

Mountain Navigation - Relocation


  1. Take a compass bearing to a feature, and after converting it to a grid bearing, place one of the top corners of the compass baseplate on the feature identified on the map.
  2. Carefully manoeuvre the compass until the orienting lines in the housing line-up with the north-south grid lines on the map, being sure to keep the corner of the baseplate on the feature and the orienting arrow pointing north.
  3. Your position now lies somewhere along the long edge of the compass base plate, you can now plot this line on the map using a pen, (see red lines above).
  4. Repeat this for one or more features to pinpoint your position, depending on the accuracy with which you took the bearings your position will lie at the intersection of these lines.


Article by Russ Mills – Mountaintrails

These, and other navigation techniques, can be found in ‘Navigation in the Mountains’, published by Mountain Training and available through our website shop here:

Autumn is definitely upon us, the clocks go back at the end of October, reducing the amount of available daylight in the evenings; and we have already experienced the first hail storm of the season as we climbed Lugnaquilla mountain recently.

Despite the gathering gloom and the cooler days, autumn also brings with it some great opportunities for the hiker and mountaineer.  The quality of the light becomes magical, and the golden glow from the sun is reflected back by the russet yellows and browns of the autumn leaves. Descending a hill at sunset, with crisp clear air and a stunning sunset is a special moment to savour.

But as the seasons march on, and autumn turns cooler, the weather in the mountains becomes more unpredictable. It gets a lot colder as you gain height, and a cool day in the valley can become an icy blizzard on the high tops.  To keep comfortable and safe in these conditions there are a few items of cold weather gear we need to add to our rucksack.

A head torch is essential winter gear

Head Torch

Remember, the clocks go back one hour at the end of October, and as a result it gets dark much earlier, at around 17.00. This seems to catch out unwary hikers every year, and the Mountain Rescue organisations are constantly reminding us to carry a torch.  Being caught out in the mountains in the gathering darkness can be an unnerving experience for those not used to hiking and navigating in the dark. Don’t be the one surprised by the shorter daylight hours and be sure to carry a torch, preferably a head torch, with spare batteries.

Hat and Gloves

Seems obvious doesn’t it?

Lightweight summer gloves won’t cut it in the cold wintry winds that rake the summit ridges at this time of year. Make sure to upgrade your gloves to take account of this, a waterproof fleece lined pair are best.  Remember to take spares too. If you lose a glove, (and I am forever finding odd gloves lost in the hills), your hands can become painful and numb and you will lose dexterity and be unable to perform basic tasks.  I am often replacing clients thin gloves with warmer ones once out in the hills, as they begin to feel the cold.

My favourite combination would be a pair of light liner gloves coupled with fleece over gloves, and a pair of winter gloves in the pack just in case. With my spare fleece gloves that makes four pairs in my kit!

Don’t forget your warm beany hat; you can lose a lot of heat from your head on a cold day. Acrylic, ‘thinsulate’ or wool materials all work well, just make sure it’s brightly coloured!

Spare warm layer

It’s a good idea to pack an extra warm layer to put on when you stop for lunch or get delayed. This might happen if there is an injury to one of your party or if you are forced to rest in an exposed position.  This could be a fleece jacket that you put on under your waterproof. Remember that fleece is a good insulator but is not windproof, so is ineffective as an outer layer in windy conditions.

I prefer a lightweight synthetic insulated jacket with a windproof outer layer. This works just as well when wet as it does dry, and can be put on over your existing wet jacket if necessary.

Waterproof shell clothing

You will be carrying your waterproof jacket already, but at this time of year it can be really put to the test, so make sure it is clean and re-treated before the autumn storms set in.  Don’t forget to pack waterproof pants too, if the rain is running off your jacket it will soak your legs if they are not equally protected.

Boots and gaiters

Make sure your boots are up to the task.

Fully waterproof boots are essential at this time of year, fabric boots are popular as they are light weight and relatively cheap, but they won’t keep you dry over a prolonged period in the boggy ground of Ireland.  If you can, upgrade to a leather pair, they will last longer and keep your feet warm and dry through autumn and winter hikes for many years.

Wear gaiters to protect the uppers of your boots and to keep the mud and debris off of your trousers.

Mountain shelter

A mountain shelter or bothy resembles a large orange tent without any poles. You can throw it over your head and sit on the ‘hem’ to keep it stable.  Inside you will be warm and dry, out of the worst of the weather. You can eat your lunch, take a break, or attend to an injury in relative comfort.  They are an important addition to your cold weather gear, and come in a range of different sizes.

Head torches are essential gear in the winter

Map and compass

You should always carry a map and compass with you, even if you are familiar with the route.

There is a greater risk of the summits being enveloped in cloud at this time of year, and poor visibility should be expected.  Take a spare map too, in case one gets blown away, and ensure they are laminated, or protect them with a soft map case, as a precaution against the weather.

Don’t rely solely on technology, though there is a place for phone apps and GPS, they are great as a back-up to your map skills, and they should not be used in isolation. These units can fail when they get wet, or too cold, or when the batteries die.

If you are not confident in your map and compass skills, attend one of our mountain navigation courses, held regularly through the year.

Wrap up warm for winter hiking

The cold weather gear above doesn’t weigh as much as you might think, and will keep you safe and comfortable when hiking in the mountains during the colder months.

The reassurance gained from knowing you have prepared for the worst will make it all worthwhile!





A grid reference is a series of letters and numbers that defines a unique square on a map, the more digits used the greater the accuracy and the smaller the square. Every country has its own unique grid, the lines are aligned north-south and east-west, forming a series of squares.

Irish grid system
Fig. 1 – The Irish grid system.

In Ireland the grid is divided into squares 100 kilometres x 100 kilometres (1 kilometre is a thousand meters).

There is a datum point set off the south west coast, which defines the 0 point, and each 100 km square is measured from here. The Irish grid is 500 km x 500 km and gives 25 squares in total.

Each square is represented by a one letter code, with the exception of I, which could be mistaken for a 1. See Fig. 1.

These 100 km squares are then subdivided further into smaller squares, each one being 1 kilometre across.

These 1 km squares are depicted on maps as blue numbered lines running north-south and east-west respectively. They are individually labelled using the ascending numbers 00, 01, 02, 03 etc… all the way up to 99.

Fig. 2 - 1 kilometre square on a 1:50 000 scale map, in this case the square 79 09.
Fig. 2 – 1 kilometre square on a 1:50 000 scale map, in this case the square 79 09.

The numbers along the bottom of the map, which increase towards the east are called Eastings , those numbers that are running up the side of the map and increase towards the north are called Northings.

When writing down a grid reference we first quote the Eastings then the Northings.

This can be more easily remembered by the saying along the hall and up the stairs’.

We can define a given 1km square by first giving the 100km square box letter and then the 2 numbers for the Eastings followed by the 2 numbers for the Northings.

In the example in Fig. 2 the highlighted square is in the Slieve Mish mountains of Dingle, in the 100km grid square Q (see Fig. 1), the Eastings are 79 and the northings 09. It is written Q 79 09 and is known as a 4 figure grid reference.

The 1 km box can be further subdivided into one hundred 100 metre x 100 metres squares, ( these squares are not shown on the map).

This now allows us to define an area of land 100 meters square, (see red box in Figure 3), and is called a six figure grid reference.

Fig. 3 - Dividing a 1 km grid square into smaller 100 metre squares.
Fig. 3 – Dividing a 1 km grid square into smaller 100 metre squares.

The extra numbers needed are not shown on the map and must either be estimated or obtained more accurately using a Romer, (found in the top right hand corner of your compass).

 The corner of the Romer is placed on the point to be identified and the numbers are read off where the Romer intercepts with the grid.

In the example in Fig. 4 the red dot has an easting of 5 and a northing of 7.

Grid references can be further used to accurately define a point on a map down to a 10 metre square, these are eight figure grid references.

Fig. 4 - Use the Romer scale on your compass to accurately read the grid reference.
Fig. 4 – Use the Romer scale on your compass to accurately read the grid reference.

A grid reference is important information, it allows you to inform others of where you are, (for example Mountain Rescue), and also allows you to locate features or a position on a map when given to you by someone else.

This article was written by Russ Mills of Mountaintrails, who provide navigation training and Mountain Skills courses in Ireland.

More information on our navigation courses can be found here: Mountaintrails Navigation Courses.

Setting the map is a fundamental navigational skill that all competent mountain navigators should be familiar with.

When you open out a map, you intuitively hold it rather like a newspaper, so the writing can be read the correct way up. The straight lines you see running up and down the map are the north/south grid lines and the top of the map points to grid north.

But north on the map is not necessarily lined up with north on the ground, in the landscape around you. By lining up, or orienting, north on the map with north on the ground you are setting the map.

But why do we want to do this?

When the map and ground are aligned together, then a hill to your right will be also be to the right of your position on the map; and a river to your left will be seen as a river to your left on the map. As long as your current position is known, this enables you to transfer your intended direction of travel on the map to a direction of travel on the ground, and can avoid costly errors and confusion.

It should be the first thing you do when looking to start a new navigation leg.

Setting the map can be done in one of two ways.

  • By aligning it with the features you see around you and can recognise on the map, such as hills, rivers, buildings and forests.
  • By using your compass, this method is useful when there are few visible features; if you are in a forest for example, or visibility is very low.

Setting the map using features

Stand with the map held in front of you and rotate your map and yourself together until features you see in the landscape line up with features you can identify on the map; a hilltop in the landscape with the corresponding hill on the map, or a lake with the corresponding lake on the map. You should be able to draw an imaginary straight line between you, the feature on the map and the feature in the landscape.

Setting the map using features in the landscape - in this case aligning with a lake.
Setting the map using features in the landscape – in this case aligning with a lake.

Your map is now set, and if you know your current position, you can identify your direction of travel on the ground.

If you are not sure of your position setting the map will also help you find your approximate location; by identifying several features on the ground and their distance from you, and translating that onto the map. This is a simple, but effective, re-location technique.

Setting the map using a compass

If there are no suitable visible features to align with the map, if you are in a forest or visibility is poor, then it is possible to set the map using a compass.

The red end of your compass needle points to magnetic north, and by lining this up with the north/south grid lines on the map you will have set the map to a reasonable degree of accuracy.

For complete accuracy you would need to take account of the magnetic variation, the difference between grid north and magnetic north at your location. It will change with time, and depending on where you are. The magnetic variation for your location will be found in the margins of your map, usually with the legend, and should be added or subtracted from the 0° bearing accordingly.

Setting the map with a compass - the three steps
Setting the map with a compass – the three steps

Setting the map in this way can be done in three straightforward steps.

  • Rotate the housing (dial) of the compass until the red orienting arrow in the housing is aligned with the direction of travel arrow on the compass baseplate. The bearing should read 0°, or north, adjust for magnetic variation at this point if you feel it necessary.
  • Place the compass on the map and line up the edge of the baseplate with the north/south gridlines on the map.
  • Carefully holding the map and compass together, and keeping them horizontal, rotate them together until the red end of the magnetic needle is aligned with the red orienting arrow in the compass housing, (also called putting red in the shed!).

The map is now set, (facing north), and by taking away the compass and holding the map steady you can now determine your direction of travel on the ground.

Mountaintrails are a guided hiking and mountain skills training business in Dublin, Ireland.

You can find out more about their navigation courses by checking out the Mountaintrails website.


Accurate mountain navigation in misty conditions is one of the most important skills you can learn as a hillwalker. Mountain Rescue teams are regularly called out to hikers who have become disorientated by poor visibility in the mountains.  Always carry a map and compass, and have the skills to use them.

However, even the best navigators can make mistakes. By following the tips given below you can avoid making some of the common navigation errors and minimise the chances of becoming disorientated in the mountains.

  • In poor visibility, always take a bearing from a summit to determine your direction of onward travel. You may think you know the right direction to go, but a short distraction for a photograph or a rummage in your pack and you can quickly become disorientated and head off the wrong way. Taking a bearing from the map will ensure you leave the summit in the direction you intended to.
  • Always estimate your bearing first. For example, if your intended direction of travel is approximately due east, then the bearing will be in the region of 270°. If it is not then you know you have made an error, and need to check it again.
  • Remember to allow for magnetic variation, this usually means a small adjustment by adding a few degrees to your bearing. The magnetic variation differs depending on your location, you can find it somewhere in the margins of your map, usually in the legend. Check it out before you leave home and remember it, or write it down on your route card.
  • Write down any important bearings that might be needed during the day. This will avoid fiddly compass work in a possibly wet and windy location, and will reduce the chance of errors. You can write them into your route card. This is your overall route for the day, broken down into a series of ‘navigation legs’, with the essential information such as distance, bearings, height gain and escape routes, written down in the form of a chart.
Introduction to Navigation course - Route card
Route card for Moel Siabod in Snowdonia.
  • Make sure you keep your compass away from magnetic and metallic objects at all times, and especially when taking and walking on a bearing. They will deflect the needle in the compass and lead to navigational errors you won’t be able to correct later. Long term exposure of your compass to a magnetic source, such as your mobile phone, can result in permanent damage and reversed polarity of the needle, so store your compass in a location well away from your phone and other electronic devices.
  • When placing the compass on the map to take a bearing, remember to face the direction of travel arrow on the base plate AWAY from your current position and TOWARDS your target. This will avoid the classic error of the bearing being 180° out.
  • Accuracy is everything when taking a bearing, a small error in your measurement can lead to you missing your target completely in poor visibility. This is especially true over longer distance ‘legs’ as the error margin increases the further you travel.
  • Keep your map and compass flat (horizontal) when taking your bearing. Better still, go down on one knee for a more stable position with some protection from the wind and rain, rest your map on the none kneeling leg.
Introduction to Navigation course - Brockaghs
Accuracy is paramount when taking a bearing, even a small error can lead you a long way off route.
  • To ensure you are not wandering off your bearing it can be useful, while your start point is still in view, to take a back bearing. Turn to face your start point and line up the white end of the needle with the orienting arrow, rather than the red The direction of travel arrow should now be pointing at the start point. If it is not move sideways until it does, you are now on the right bearing and can turn back to face your travel direction.
  • Remember to measure the distance from your start point to the target. You can now pace this distance, or time it with your watch, to know when you should be at the target point.
  • It’s a good idea to keep a timing card in your pocket or somewhere handy. This has written on it the time it takes to walk over a range of distances at a variety of walking speeds. It will speed up your calculations and help eliminate errors when you might be cold and tired on the mountain.
Introduction to Navigation course - timing card
A timing card will make distance calculations easier and avoid errors.
  • Make sure the orientation arrow of the compass is pointing north when you are taking a bearing, have the top of the map, which always points to grid north, facing away from you. If you inadvertently line up the orienting arrow pointing south, the bearing will again be 180° out, an estimation of the bearing as above will soon pick this up.
  • If you struggle to manipulate the compass housing when wearing bulky gloves, try wearing lightweight liner gloves underneath. You can then remove the outer gloves and use your compass while still giving your hands some protection from the weather.
  • You should try to have up to three features of your target location that you can identify to help you confirm you are in the right place. A further feature, called a ‘catching feature’ should be identified from the map, and will tell you when you have overshot the target.
  • If things don’t look right and you are entirely unsure about your position, you can line up the white end of the needle with the orienting arrow. The direction of travel arrow on the compass housing will now point back the way you have just come. You can follow this back to your starting point, (your last known position), and begin the process over again.
Navigating across open country.

If you want know more about poor visibility navigation, you can join one of our navigation courses for novices and improvers. Held at weekends throughout the year you can find out more on our website at: Mountaintrails Navigation Courses.

Russ Mills owns and runs Mountaintrials, he will be giving a talk on avoiding navigational errors on Wednesday 30th March at 7.00pm, at Basecamp Outdoor Store on Abbey St. in Dublin.

More and more of us are taking up hiking as a way of getting fitter, enjoying the fresh air, (a moot point perhaps when it’s grey and raining), meeting like-minded people and exploring the natural environment.  For some, heading out into the mountains for the first time can seem daunting, and it can be reassuring to join up with others in a club setting, or go with a more experienced friend or a guide.  Once you have ventured out a few times and listened to conversations about different clothing and equipment, the best routes to take, the secret of good navigation and even what’s in the sandwiches, you realise there is a lot more to this hiking business than you first thought.

Perhaps you feel you don’t want to be just one of the followers in a group any longer, maybe you want to plan and choose your own routes, and to have the confidence and the ability to take to the hills independently.

This is where the Mountain Skills scheme comes in.

Mountain Skills is a comprehensive navigation and personal skills course that will equip you with the basic knowledge and skills to enjoy the mountain environment in safety.  It is administered by Mountaineering Ireland, who appoints individual ‘providers’ to deliver the courses.  It is divided into three parts, Mountain Skills 1 and Mountain Skills 2 are the two training modules, and they each take two days to complete. The third part is the assessment, also over two days. There is no obligation to take all three parts, but you should clearly start with Mountain Skills 1 and progress from there.

Mountain Skills course with Mountaintrails

Navigation is an important aspect of mountain travel, and poor navigation is the single most common cause for calling out a Mountain Rescue team. No surprise then, that navigation features as a large part of the Mountain Skills syllabus. It’s not all about being able to use a compass; reading a map, relating it to the ground, estimating distance and recognising topographical features, these are all important parts of the navigators ‘tool box’.  Mountain Skills teaches you when and how to use each one to move safely and proficiently through the mountains.

The Mountain Skills scheme will also teach you how to recognise and deal with mountain hazards; the environment, weather, hypothermia and terrain hazards are some of the topics covered.  Personal equipment, movement skills and what to do in the event of an emergency are also looked at in detail.

Mountain Skills is not a leadership qualification, but it is a prerequisite if you wanted to move on to higher qualifications such as the Mountain Leader award.

To quote Mountaineering Ireland, “Mountain Skills is a foundation for personal mountaineering proficiency”.

Night navigation on a Mountain Skills course

Many hikers are now taking part in the Mountain Skills scheme, and see it as a great way to acquire the basic skills for safe and enjoyable mountain days, or to fill the gaps in their hillwalking knowledge.

More details of the scheme can be found on the Mountain Skills page of our website, or on the Mountaineering Ireland website.

Mountaintrails has been accredited by Mountaineering Ireland to deliver Mountain Skills courses.

Accurate navigation in winter is all the more imperative.

With the shorter daylight hours comes the increased likelihood of you having to descend in the dark. There is the increased risk of poor visibility, or even white out conditions when windblown snow particles can blur the boundaries between earth and sky, (known as the ‘white room’).  Paths, streams, boundaries and even lakes can disappear under a blanket of snow.

Good navigators know where they are at all times, and can follow their progress on a map. This is so important in winter conditions, when icy snow slopes and corniced edges can increase the hazards you face.

The essential tools for winter navigation are the map and compass, an altimeter can be useful too, (more of which later).

Keep your map in a soft plastic map case, folded so the area you are hiking in is shown. This should be kept handy, inside your jacket or in a secure pocket, it’s no use to you in the bottom of your rucksack, get it out and use it.

Your compass should be of a high quality, the mountaineering bodies in Ireland and the UK recommend the Silva 4 Expedition model. Use the lanyard to fix it to your rucksack strap or a toggle on your jacket, so you won’t lose it, and remember to keep it away from electronic devices, as these will deflect the needle and give inaccurate readings.  In the windy conditions often experienced in winter maps and compasses can easily be blown away and lost, so practice good map management, (and carry a spare just in case).

Don’t be tempted to rely on GPS or phone app systems for your navigation, they can be a useful back up, but cold kills batteries and your unit may fail, leaving you stranded.

Hollyhike 3
Winter conditions experienced in the Wicklow mountains, Ireland.

Preparation is the key. It is important to check the weather forecast several days before you go, if there is a risk of snow check out any available avalanche forecasts too. Do not try to take on too much, progress is slow in winter and daylight hours are few. Plan your ascent and descent routes taking into account potential hazards and plan an escape route in the event of abandonment. Draw up a route card and break down your journey into a number of navigation legs, try to keep the legs short to reduce inaccuracies when navigating in poor visibility.

When beginning any navigation leg, or trying to determine your position, the first thing to do is to orientate the map. This is also called setting, and involves lining the north south grid lines on the map with north on the ground. In good visibility this can be achieved by sighting features in the landscape and lining them up with the corresponding feature on the map. In poor visibility you may need to orientate the north south grid lines with north by using the north (red) end of the compass needle.

Sometimes this may be all you need to do to determine your direction of travel and to identify your objective, but in poor visibility it may be necessary to walk on a bearing.

Navigating at night is the ultimate in poor visibility navigation and requires skill and accuracy.

When navigating in poor visibility consider the 5 D’s before each leg; Distance, Direction, Duration, Description, Destination.


Measure the distance to your next target using either the compass romer or the measuring scale on the edge of the housing. To know how far to walk you should use either pacing or timing, or both.  Pacing is the technique of counting the number of double paces to your objective. Knowing how many paces you take to walk 100 metres in different conditions and terrain, you can then count out the multiples of 100 metres until you reach the distance measured. Pacing works best over shorter distances of several hundred metres, for greater distances timing is often used. Timing relies on knowing how fast you are walking, say 4 km/hr, and doing a calculation to determine how long it will take you to reach the objective.

These techniques may sound complicated, but they are one of the cornerstones of good navigation, and become easier with practice.


To determine which direction to walk in you must take a bearing from the map with your compass. Estimate it first, this will help avoid errors, particularly the often made 180 degree error, where south is mistaken for north on the map, or you have the compass pointing from the objective to your current position instead of the other way round.

Once you have your bearing you must adjust it to take account of the magnetic variation between magnetic and grid north, check the map before you set out as the information you need is in the legend. Sight along the compass to an object in line with the bearing and walk to it, repeat this process until you reach the objective.

If visibility is so poor you cannot see anything ahead, send a companion ahead of you and adjust their position until they are in line with the bearing, walk toward them and repeat the process.

Taking and walking on bearings can seem daunting, and requires training and practice, but there are a number of online resources to help, some useful sources are listed at the end of this article.


What do you expect to see when you reach the objective? You should have at least 3 features or characteristics of the target to enable you to confirm you have arrived in the right place. When you reach the objective ask yourself the question, ‘Do I see what I expect to see?’

To avoid overshooting, determine what feature will tell you that you have gone too far, this is a catching feature, and could be a stream, a change of slope, or a boundary.

It is a good idea to identify features you might see or cross on route, by noting these features as you pass them you can confirm your position. These are called tick features as you ‘tick’ them off as you go, they also give a good deal of confidence that things are going according to plan!


How long will it take to reach the objective? This is linked to the timing mentioned earlier, and again you need to know how fast you walk and the distance to the objective.

The winter mountains bring challenging but wonderful days out. The south ridge of Snowdon, North Wales.

Altimeters are a very useful tool in winter navigation. It can be important to know how far up or down a slope you are, particularly if you have to make a change of direction when descending a spur. By reading the contour height from the map and relating it to the altimeter reading it is possible to accurately determine your position. Remember to calibrate the altimeter regularly at spot heights and summits, as they often rely on barometer readings, which can change rapidly in winter.

Finally, if it all goes horribly wrong and you can’t recognise anything in the landscape, don’t panic. Take a breather, have a warm drink or a sugary snack. As long as you have been walking on your bearing and know how far and how long you have been walking, you can always turn your compass by 180 degrees and return to your last know position, the beginning of the navigational leg. This is a back bearing and can return you to a place you can identify on the map, from here you can re-calculate the 4 D’s and begin the leg again.

Winter hiking carries it’s risks, but the rewards can be immense

Navigating in winter will test the skill of the best navigators, and requires all the above techniques and a lot of practice to become completely proficient. However, when you have learned the skills and gained the experience the winter mountains are open to you in all their magical beauty.

If you want to learn to be a competent and self-reliant winter navigator you can join one of our Mountaintrails navigation courses.

Other useful resources:

British Mountaineering Council:

Mountaineering Ireland: