Grid references

BY Eva

Reading and plotting grid references

A grid reference indicates a location on a map in terms of numbered vertical and horizontal grid lines. Grid references are useful for sharing routes, and quickly communicating to emergency services. Bushwalkers often share grid references of campsites or camp caves, obstacles or challenges on a walk, where to get through a cliff line, where to cross a river or what route to take. Orienteering competitions also provide information on their flag locations using grid coordinates.

To share a grid reference, the name of the map must be given, plus the X and Y coordinates. Users must also be clear on the reference system used.

Reference systems Understanding reference systems used by bushwalkers

When sharing a grid reference, bushwalkers must be clear on the reference system being used, else the points will not necessarily match up. Maps that show the same terrain can be made using different datums and projections, meaning that the grids do not necessarily line up.

For example, compare the images of the Megalong Valley below, and notice that the location of all features relative to the grid lines is different. This is because the first map below uses an older datum than the one below that.

AMG

MGA / GDA94

Any given reference system is based on a datum, a 3D representation of the earth, and datums differ in how they represent land and where the location of the central frame is. Two points can be out by as little as a few hundred metres, or as much as several kilometres if there is confusion over the reference system in use.

Maps usually have an information section that identifies the map datum and projection, along with the publisher and copyright information. When communicating a grid coordinate, state the coordinate system first, then the grid coordinates.

In NSW, the 1:25000 topographic maps use either the AMG or the MGA coordinate systems.

AMG: The AMG is the Australian Map Grid 1966/1984 system and was used on the old series maps, mostly distributed circa the 1980s. The AMG reference system uses the Universal Transverse Mercator projection of the Australian Geodetic Datum 1966.
MGA: The MGA is the Map Grid of Australia 1994, and is used in all the new series maps. As a general rule, all the new series maps have an aerial photo image on the reverse. The MGA reference system uses the Universal Transverse Mercator projection of the Geocentric Datum of Australia 1994 (GDA94).

The AMG system was used until roughly the mid-90s when it was replaced with the MGA system, which is more compatible worldwide as the GDA 94 datum is almost identical to the WGS84 datum used in GPS (Global Positioning Systems). The result of the change from the AMG system to the MGA system is a shift of approximately 200 metres in a northeasterly direction.

While being off by 200 metres doesn’t sound like much, in the bush this can be disastrous for an emergency operation, or cost a bushwalking party serious time delay. That’s why it’s important to communicate which reference system is being used and to know how to convert between them. In an emergency, it may be possible to get enough mobile phone coverage to contact the emergency services and communicate the location of rescue.

Converting between AGM and MGA

The shift between AGM and MGA is approximately 200m in a northeasterly direction. The images below give an example of the shift relative to the UTM Northing and Easting grid lines.

AMG

GDA

To convert between grid points, users add 100 m to the Eastings, and 200 m to the Northings. As a practical example, for a 6-digit grid reference, add 1 to the Eastings (the first three digits), and 2 to the Northings (the second three digits). So the junction of the two roads Hampton-AMG436645 becomes Hampton-MGA437647. The examples below have more information on reading grid references.

Since all objects on a map remain the same relative to each other between the two systems, bearings do not change.

Reading a grid reference from a map Learning how to read a grid reference from a map

Maps have numbered vertical and horizontal grid lines that enable the reader to identify and communicate a particular location on the map. The vertical lines are aligned with grid north, and the horizontal ones are exactly perpendicular to the vertical lines.

The Universal Transverse Mercator (UTM) system, which describes a point in terms of metres, is most commonly used by modern topographic maps. And this is the system described here.

In the UTM system, the vertical lines are called Eastings (i.e. they help locate how far east the point is), and the horizontal lines are called Northings (i.e. they establish how far north the point is). Most maps also include the Longitude and Latitude of the map at the corners (i.e. a reading in degrees, minutes and seconds).

A UTM grid reference tells the reader how East and how far North to go on the map. It consists of two parts – the Easting digits, and the Northing digits – and always has an even number of digits. Determine the number of Eastings and Northings digits by dividing the whole grid coordinate by 2. The more digits, the more accurate the grid reference.

When reading a grid reference, Eastings always come first, followed by the Northings. A simple way to remember this is the saying ‘cross the creek before going up the tree’, that is, go horizontal first, then vertical.

Example 1: Describing the location of the hill labelled 619. The 619 refers to the height of the hill in metres. Often, bushwalkers describe a hill by its height, unless another name is written on the map (typical for popular and distinctive hills). In this example, since the hill has no name it can be called Hill 619.

On the 1:25,000 map above, each square is 1km wide and high. The Northing and Easting lines are all numbered. Ignoring the small numbers either side of the black numbers (explained later), notice that the lines increase by one unit along the bottom (68, 69, 70, 71…) and up the left-hand side of the map (05, 06, 07, 08…).

A four digit grid reference (2 digits for the Easting, and 2 for the Northing) is a crude measure of the location with an accuracy of one square kilometre. It describes the intersection of two lines. The closest intersection to Hill 619 is the intersections of the Easting line 69 with the Northing line 06. Hence Hill 619 has a four digit coordinate of 6906 plotted as a white circle below.

However, since the margin of error in a four digit this grid coordinate is 1km square (outlined in orange), this reference could describe any of the features from the hill in question, to a gully or a creek junction. To more accurately describe Hill 619, it’s best to use a six-digit grid reference.

Draw perpendicular lines from Hill 619 to intersect with the Easting and Northing lines. Then measure how far along the grid the lines are. For the Easting, the line crosses 6/10th of the way along the grid. Hence the Easting coordinate is 686. For the Northing, the line intersects 1/10th of the way up. Hence the Northing coordinate is 061. The Hill has a six-digit grid reference of 686061. Since the map is an old map (‘1:25,000 Colo Heights’) and uses the AMG reference system, the six-digit grid reference is ‘Colo Heights AMG-686061’.

A six figure coordinate has six figure grid reference an accuracy of 100 m2, indicated in the orange square box. This area of error is much smaller than the search area provided by a four-digit grid reference.

Example 2: Bonnum Pic.

Care must be taken to quote all the zeros in the right place. In this example, the Northings have a zero at the front. The 6 figure grid reference is therefore 477060. Since the map is a new edition map and uses the MGA reference system, the six-digit grid reference is ‘Hilltop MGA-477060’.

Example 3: Hill 2122. The hill lies on a grid line meaning that for a six-digit grid reference, the Easting has to include a zero at the end. Hence the six-digit grid reference of Hill 2122 is 010977. Since the map is an old map (‘1:31680 Caoura’) and uses the AMG reference system, the six-digit grid reference is ‘Caoura AMG-010977’.

Example 4: Hill 731.

An 8-digit grid reference is even more accurate than a 6-digit one and has an accuracy of 10 m2. Supplying accuracy to the nearest 10 metres involves splitting up the grids into 100-tick increments.

Hill 731 has an eight-digit grid reference of 49029349. Since the map uses the MGA reference system, the eight-digit grid reference is ‘Hilltop MGA-49029349’.

UTM zones: Identifying the region
UTM divides the earth into 60 zones each with 6 degrees of longitude, and 20 designators each with 8 degrees longitude.

© Jan Krymmel, 26 Jan 2007 / Wikimedia Commons / CC-BY-SA-3.0

Australia falls between zones 50-56, and Sydney is in 56H.

A 6-digit grid coordinate system works well among bushwalkers to communicate points of interest and routes, and Bushwalkers use a shortcut to identify the region in question. They refer to the name of the map in question, a practical and quick solution for sharing information.

However, on a global scale, there would be many identically-numbered grid locations unless the specific UTM zone is also reported, along with a context for the Easting and Northing lines.

In the corner of all maps, the Eastings and Northings are given additional small numbers before the main ones that identify the lines.

While the small numbers aren’t usually quoted by bushwalkers for six- or eight-digit grid references, they will appear on a GPS reading. GPS Eastings and Northings always include an accuracy down to the nearest metre. Hence for every square kilometre, the accuracy has to be to 3 digits for Eastings and Northings, something that is hard to do when reading off a map, but if given these grid coordinates, it’s possible to plot accurately.

Hence, the full coordinates of Hill 731 are Zone 56H, 0269210mE, 6316890mN. This is the same eight-digit grid calculated in example 4 above in orange.

Plotting a grid reference on a map Learning how to plot a grid reference on a map

Plotting a grid reference on a map is the reverse process of reading it on the map.

Example 1: Plotting the grid reference ‘Caoura AMG-041948’, the junction of a creek with a major river.

The reference 041948 is a six-digit grid reference with a 041 Easting and 948 Northing. Find the 04 Easting line and follow it 1/10th of the way further east. Then find the 94 Northing line, and follow it 8/10th of the way further north. The grid point is the junction of Paradise Creek with the ShoalHaven.

Example 2: Plotting the grid reference for Mt Wangandarry ‘Hilltop MGA-48259765’, a trig point.

The reference 48259765 is an eight-digit grid reference with a 4825 Easting and 9765 Northing. Find the 48 Easting line and follow it 25/100th of the way further east. Then find the 97 Northing line, and follow it 65/100th of the way further north. The grid point is the top of a knoll on a large flat hill top.

Tools
Coordinate plotting tools can aid plotting grid points on maps. Grid tools enable the user to keep an exact right-angle position as they find the coordinates they’re looking for, and the user does not need to draw lines on the maps.

A UTM plotting grid is one option. Alternatively, a corner style tool or simple ruler. Ensure that any map plotting tool has the right scale (note that American sellers stock 1:24,000 tools, not to be confused with the more common 1:25,000 series used in Australia).

Using a GPS to identify and plot locations How to use a GPS to identify and plot your location on a map

GPS units are an excellent tool for identifying and plotting locations along a bushwalk. GPS units can also be loaded with a basic topographic map and route plan at home, and users can follow the route in the field. Alternatively, users can identify specific locations along the walk and translate them back onto a topographic map to double check their location and accuracy of navigation.

GPS units act as an additional navigation tool to traditional map and compass. They typically give accuracy up to 20 m but rely on good satellite coverage. GPS units fail in regions where the sky is partially or wholly obstructed (caves, cliff lines, canyons).

Before use set the GPS unit to the correct Geographic Coordinate System, based on the type of maps being used. The most common system that bushwalkers use is the UTM/UPS system (not latitude/longitude). Then select the appropriate datum: for new series maps use WGS 84 (or GDA 94 as they are essentially the same); for old series maps use AGD66. If unsure, read the fine print in the publication details of the map. All datum and reference modifications on a GPS can be made in the ‘settings’ section.

Reading a grid reference on a GPS

A GPS grid reference looks something like this:

It includes information on the Geographic Coordinate System used (UTM), the location zone (56H), the Eastings (0706832) and the Northings (4344683). Eastings are always given first.

The ‘706’ part of the Easting information refers to a major Easting line, and the ‘832’ gives the location down to the nearest metre. The ‘4344’ part of the Northing information refers to a major Northing line, and the 683 gives the location down to the nearest metre in the grid.

Translating a GPS reading onto a map

Example: Finding the GPS coordinate Zone 56H, 0304920mE, 0695440mN.

The map below is in Zone 56H. Major Easting lines are 04, 05, 06, etc. and all have a ‘3’ at the start. Major Northing lines have 95, 96, 97, etc. Eastings have a ‘3’ prefix shown on the map, which is ‘03’ in the GPS coordinates. Similarly, the Northing lines have a ‘6’ prefix shown on the map, which is ‘06’ in GPS coordinates.
Hence, the 8-digit grid reference is 04929544. Follow the Eastings along to the 04 line, and then 92/100th further east. Follow the Northings to the 95 line and 44/100th further north.
The location is Mount Woolnough.

map reading

Map care

BY Eva

How to care for your maps

Maps are amazingly detailed descriptions of the land and very useful for navigating in the bush, but they are vulnerable to weather, and poor care. Torn, damaged maps are harder to read and can leave a group in a tricky situation if they are relying on a single map that gets damaged.

Since maps also may have to last a long time, it helps to take care of them. Some bushwalkers choose to use photocopies instead and transcribe routes/passes and notes to the originals at a later stage. Ensuring that there are backup maps in the group is also very sensible as it’s easy to drop a map in water or lose it in thick scrub.

A pencil is recommended for marking routes or passes on a map. Use light lines so they may be erased quickly without smearing and smudging or leaving marks that may cause confusion later. Back home, consider going over the pencil additions again with a harder pencil or ink pen.

Copying The legalities behind photocopying maps

Photocopying sections of a map and using them in the field is a good way of protecting the original. Under copyright laws, a certain amount of photocopying of maps for personal use is ok, although it is a bit of a grey area. Some maps give permission for photocopying under “fair dealing”, others specify that no part of the map may be reproduced. Bushwalkers intending to photocopy maps are advised to check with the Australian Copyright Council, and/or the producers of the map.

The main disadvantage of using photocopied maps is that any handwritten notes made during the trip have to be transcribed to the original. Transcribing back and forth introduces errors. The other issue is that writing can be harder to see on a photocopy. Best to make sure that all notes are made in clear black pen, and the writing is easily legible.

Map case Why map cases are helpful

Maps are documents printed on paper and require protection from water, mud, and tearing. To prevent maps from getting damaged, where possible, use a waterproof map case, or keep it in a pocket, or in some other place where it is handy for use but still protected.

Choose a map case that is waterproof, and has a cord so that the map can rest around the neck. Ideally, select a map case that is large enough to fit two sections of the map, and provided the map is folded correctly, it’s easy to transition between segments even in bad weather.

Folding maps How to fold topographic maps

Shop-bought maps are typically folded in a peculiar way that means the user has to open up the entire map every time they move off one folded section and onto another. On some trips this can happen as often as once and hour. And while it may be possible to get away with unfolding and refolding the map every few kilometres in good weather, it gets much harder in the rain and wind.

For bushwalkers, a better technique is to fold the map down the middle and then concertina it. Do this in the comfort of the living room at home rather than the bush to make sure that the map creases are all folded neatly.

The US army also recommends the above method (diagram below, left image) or folding the map small enough to fit in a pocket (diagram below, right image). The folded map is still available for use without having to unfold it entirely.

map reading

Digital maps

BY Eva

Using digital maps on a bushwalk

While some people love owning a physical map collection, others prefer to read from a phone or iPad, or print their digital maps as they need them.

The advantage of using a digital map is that it’s possible to get the information for very cheap or free depending on the region. Digital maps can be printed, meaning that bushwalkers only need to carry with them the exact area they need to use. It’s also possible to access maps on smartphones and tablets, and since most people have these devices, so that’s an easy way to give access to many.

The disadvantage of using a digital map from a digital device is that it’s more complex to make notes and draw tracks on digital devices. Also, the battery of the device can run out, and it can be challenging to use the device in the rain. If printing out digital maps, the print quality may not be high enough to read subtle features.

Use of digital maps has to be carefully weighed up by thinking through the likely terrain, and trip.

Sources Where to source digital maps from

Digital maps can be split into four categories:

Basic digital maps
Detailed topographic that can be printed out from computer
Detailed topographic that can be read from a device like a phone or GPS
Bushwalking specific

Basic Digital Maps
These digital maps are not topographic. They show some fire trails, some walking trails but are not informative enough for navigating on anything more than a well known, well-signposted track. They can be helpful to get to the start of a walk i.e. excellent urban street accuracy, pretty good for some more remote fire trails and some campgrounds.

Google Maps – FREE!
Nokia ‘Here’ Maps
Google Earth – FREE!
National Base Map – FREE!
OpenStreetMap – FREE!

Detailed topographic maps: printable from computer
These maps have excellent topographic information for navigating in remote areas, and can be printed out from a computer and used on a bushwalk.

NSW: SIX Maps (NSW Topo Maps), an online mapping tool for NSW developed by Land & Property Information NSW – FREE!; Memory Map (covers all states of AU)
TAS: Land Information System Tasmania – FREE!
VIC: Vicmap Topographic Maps Online

Detailed topographic maps: for use on smartphones, tablets or GPS units
These maps have excellent topographic information for navigating in remote locations, and can be read from phones or GPS in remote areas.

NSW: Memory map for smartphones or tablets
Global: Garmin’s maps for GPS

Bushwalking-specific
Bushwalking-specific maps offer information on specific routes or tracks and can be helpful when looking for bushwalking-specific track information. Wildwalks, NSW’s most comprehensive collection of Bushwalking track notes and maps; “Topo not to be” maps, a site for bushwalkers to map and share suggested tracks (it only covers the Greater Sydney Region from about Jervis Bay and as far north as just past Newcastle); Tom Brennan’s canyoning maps, marking major canyoning areas around Sydney.

Planning and field use Things to think through when going digital

If planning to use digital maps for a walk, make sure to download or print out the correct maps before the start of the walk where there may be little or no reception. Ensure that the print quality is high enough to read contour lines and features accurately and that any electronics have enough battery life (and spares!) for the entire trip.

In the field, make sure electronic devices are waterproof, dirt proof (e.g. water protection devices for phones), and that there are backups (spare batteries, extra devices).

For printed out maps – carry an extra set in case one set gets lost. Always print a larger map area than expected to use in case plans change.

map reading

Aerial imagery

BY Eva

How to use aerial imagery on a bushwalk

Aerial imagery is remarkably easy to come by these days and can be extremely useful in identifying interesting bushwalking features, potential routes and vegetation thickness. It’s easy to spot urban areas, constructed buildings and tracks and possible to determine elevation via shadows.

Aerial imagery means any images taken from an elevated position, including photography from helicopters, fixed wing aircraft or drones, right through to air balloons, parachutes and satellites.

A few free sources include:

Google Maps also gets its high-resolution images of cities from aircraft flying at 240 to 460 m, and the rest from satellites. LANDSAT satellites have been pivotal in providing accurate environmental data about the earth’s surface and in 2016 google earth has released worldwide images sourced from Landsat 8. Most of the satellite images are no more than three years old, meaning that the user can be confident that the information is reasonably accurate and current.

Reading and interpreting How to read and interpret aerial imagery

Just like topographic maps, manmade and natural features can be identified on aerial images. Aerial images show texture, shadow and patterns only. They do not usually include names of landmarks, roads or settlements, or information about elevation.

Landforms
Shadows help to identify elevation and relief on aerial photos. Shadows that fall outwards indicate higher elevations such as hills or mountains, whereas shadows that fall inwards indicated riverbeds, creeks and gullies. The rate of shadow appearance and disappearance along a ridgeline can determine the slope and steepness of features.

Water courses
Rivers are wide dark grey lines with many curves and bends in them. Side creeks flow into them. The v-shape of the connection between a side creek and the main creek always points downstream. Hence the reader can determine flow direction.

The colour of clear and muddy water bodies is different due to different amounts of reflected sunlight. Since clear water reflects less sunlight than muddy water, muddy water appears lighter in colour. Sandy soil also looks lighter than humid soil surfaces.

Aerial images can also give an indication of whether a water source is perennial or non-perennial, helpful when planning water sources on a walk.

Vegetation
Natural vegetation and grasslands usually have dark tints and a diverse pattern. Crops or plantations are identified by their unnaturally straight pattern of growth and patchwork appearance of cultivated lands. Tall crops appear darker in colour than small crops. Cultivated vegetation usually has a smooth, fine appearance, whereas natural bushland is dotted, and mountainous areas rough.

Manmade
Manmade objects tend to be evenly distributed with straight edges. Broad grey lines with few bends in them are major bitumen roads. Secondary roads are generally narrower with more curves. Fire trails may have a brown/orange/red tinge to them depending on the soil and road surface. Railway lines are small grey lines with long, smooth curves. Roads connect up perpendicular to each other while railway lines gradually merge.

Planning Using aerial imagery to plan a trip

Aerial imagery can be helpful in conjunction with topographic maps. They give an overview of the area, and able the user to see different patterns than on a topographic map.

From a bushwalking perspective, aerial images can be helpful to identify:

Clear ridges for easy walking
Dense scrub vegetation to avoid
Potential canyons, caves and other rock formations of interest
Perennial and non-perennial water sources for managing water needs
Cultivated (i.e. private) properties where bushwalkers cannot go without permission
Clear areas as potential campgrounds, or equally cliff-lines with potential camp-caves
New or altered fire trail or roads not shown on topographic maps

In NSW, bushwalkers use aerial imagery to detect canyoning areas. Often, the 10-20m topographic contour maps provided by the lands department are not accurate enough to determine if a creek line has or doesn’t have canyon features. Aerial imagery gives a reasonable indication of the depth of the cliff and can be helpful to figure out if the area is worth exploring.

compass

Magnetic Declination

BY Eva

What is magnetic declination and why it matters

Magnetic declination is the difference between true north and magnetic north. It changes depending on where you are standing on the earth. Bushwalkers need to take this into account when using a map and compass, as even a difference of 10° in a navigation bearing can lead to substantial navigation errors.

To recap:

True North is north, according to the earth’s axis. True north points to the North Pole.
Grid North refers to the direction northwards along the map projection grid lines. This comes from a 3-D object (the earth) being depicted on a 2D object (a map).
Magnetic North is the direction that a compass needle points to. Magnetic north is the direction of the Earth’s magnetic field lines.

The difference between True North and Magnetic North is referred to as the Magnetic Declination.

Bushwalkers can compensate for this difference by using charts of declination or local calibration that show the correct conversion (and rate of annual change). The easiest way to determine this is to use the tool in the map key that looks something like this:

The difference between grid north and true north is typically within 2°. For bushwalkers, grid north is the more relevant measurement as it allows you to use the UTM grid lines as your north reference (assuming that 2° difference between grid north and true north is an acceptable margin of error – most of this time in a bushwalking context this is fine). If the map does not have the numbers, but only intersecting lines, place the compass on the lines and measure the difference (for Sydney region, it’s roughly 12°).

on-track navigation

Different ‘Ways’

BY Eva

Recognising different kinds of pathways, tracks and trails in the bush

There are many different types of bushwalking pathways, tracks and trails across Australia. Some routes have proper concrete paths, while others are merely the faintest trace of a track. Collectively, they are known as ‘ways’, a rather awkward and confusing word considering it has other meanings too! Nevertheless, it’s the best word to describe tracks, trails, sealed pathways, metal boardwalks and so on.

While some ‘ways’ are well maintained with signposts and facilities, others have irregular signposting or none at all. Some, but not all ‘ways’ are marked on maps, distinguished by different colours and line thicknesses.

Recognising from a map the different ‘ways’ the route follows is helpful. If you have a sense of how well-defined (or not) the route is, you’ll be well prepared for sections that are vague or not well signposted. Hence if something different appears, then alarm bells sound. It gives you time to stop and double-check that you’re still going the right way.

Sealed road Features of a sealed road

Sealed roads are recognised as properly formed and constructed road surfaces made with materials such as tar, bitumen, or concrete.

Some bushwalks make use of sealed roads to connect between sections of bush or national parks. Take care of vehicles and other motor traffic when using these roads. Walk on the right-hand side of the road to face oncoming traffic.

Sealed roads are typically depicted as solid red lines on topographic maps.

Unsealed road Features of an unsealed road

Unsealed roads are categorised as routes accessible by vehicles that are not sealed, metalled, or gravel roads.

Bushwalks will commonly use unsealed roads to connect between different sections of bush. As with sealed roads, take care of vehicles and other motor traffic when using these roads. Walk on the right-hand side of the road to face oncoming traffic.

Unsealed roads are typically depicted as solid orange lines on topographic maps:

Management trail Features of a management trail

Management trails are used by land managers to access the areas they look after. They are not generally open to public vehicles. Management trails include fire-trails, which have strategic importance for fighting bushfires. They are usually an unsealed surface, about the width of a 4×4 car, with tire markings or ruts on the trail. Fire trails have contour banks to control erosion and track degradation, and sometimes passing bays or areas for vehicles to turn around.

Many bushwalks follow firetrails as they provide relatively easy walking. Although vehicles are rare, still take care when walking these roads.

Management trails are typically depicted as dashed orange lines on a topographic maps. Longer orange dashes indicate it is a vehicular track. Shorter orange dashes indicate a four-wheel drive track.

Path Features of a path

Paths are sealed walkways. They are generally flatter trails, and some are wheelchair user accessible.

In Australia, only a few of these paths exist, and they are generally short distances to a lookout.

Sealed paths, boardwalks and tracks are not generally drawn differently on topographic maps. They are represented by dashed black lines.

Boardwalk Features of a boardwalk

Boardwalks are used in areas with sensitive vegetation or boggy, muddy walking areas. They are quite common in Tasmania, as well as wetland areas. Sealed paths, boardwalks and tracks are not generally depicted differently on topographic maps.

Track Features of a track

In Australia, a track is an unsealed pathway (except Victoria, where a ‘management trail’ is a ‘management track’, and a ‘walking track’ is a ‘walking trail’). Many bushwalks are tracks, some with better signposting than others.

Sealed paths, boardwalks and tracks are not generally depicted differently on topographic maps.

Faint tracks Features of a faint track

Faint tracks are standard on Grade 5/6 walks. These tracks might be overgrown, poorly maintained, or never a track in the first place but just a pad that has developed over time. Sometimes, animals will create tracks across ridgelines or down to waterways that provide easier walking for bushwalkers.

Faint tracks are generally not depicted on topographic maps.

on-track navigation

Following the plan

BY Eva

How to follow a bushwalking plan

Before starting any bushwalk, you will make a plan. Then on the bushwalk, the navigation side of things is about following that plan, and updating it if things change.

Micro-navigation How to micro-navigate

Micro-navigation is when a navigation task is broken down into small pieces. A whole journey comprises of an infinite number of micro-navigation decisions, the result being getting from point A to point B.

Micro-navigation involves noticing the tiniest of features on a map. Things like, for instance, the number of twists in a river, a subtle change in the direction of a ridgeline, an implied knoll. Maps are a wealth of information once you start to examine these details, and they provide a much clearer picture on how you are traveling through the landscape.

Being able to micro-navigate is highly advantageous in poor weather conditions too. For instance, when visibility is poor, being able to recognise subtle nearby features could make the world of difference to understanding where you are in the landscape.

Group navigation Why your input is so important

When you’re starting out, it’s easy to feel quite self-conscious about your navigation skills compare to others that have been practicing for longer. So it’s easy to let someone else take the lead and make decisions. Remember, everyone has to start somewhere, and navigation is one of those things that only gets easier with practice.

Never be afraid to shout out when you don’t think things make sense. The more people in the group that keep an eye out for stuff, the less likely you are to go wrong. So many groups have blindly followed the person at the front only to realise half an hour later that they’ve gone in entirely the wrong direction! A short two-minute conversation to figure out where the group is on the right way can save hours of backtracking. Also, by speaking up, you’re making sure that the whole group agrees with the route decision, and encourages everyone to think about the landscape and where the route is going.

Even if you are not actively following the map on a bushwalk, follow the shape of the land and make a mental note of features you pass. Becoming familiar with these landforms trains the brain to spot quickly those features that most people would miss. A memory of the landscape is extremely useful if the group has to backtrack.

on-track navigation

Staying Found

BY Eva

How to stay found on the map

The best navigation advice is simple: never get lost! Sounds a bit stupid, but it’s true. Navigation is incredibly hard when you have to figure out where you are every hour. Better to know where you are at all times by regularly checking the map with the surroundings.

Bushwalkers that regularly follow the map are more likely to pick up things that don’t seem right. They’re keeping an eye out for where they are in relation to landforms, the direction they are traveling in, and how it changes. They’re also watching the changing distance between their current location and where they want to be.

Keeping a keen eye on the map is the best way to know where you are at all times. Here are a couple of ways to do that:

Orientating the Map How to orientate the map in the direction of travel

It can be challenging to match a map up with the terrain, particularly when your brain has to make additional calculations about the orientation of the map relative to the landscape. At some point in our lives everyone has tried to stand on their head to make sense of whether a map is telling them to go right or left. People naturally find it easier to relate a map to the surroundings when everything that is to our left on the map matches everything that is to our left on the ground. Orientating the map in the direction of travel makes life a lot easier.

This is the key to orientating a map: placing it to line up neatly with the features on the ground. Many navigation courses make a big deal about this, claiming it’s the first thing that anyone should do before navigating. In reality, bushwalkers will rarely orientate the map accurately with a compass, unless for interest to figure out the exact names of distant peaks. Instead, they tend to orientate the map so it’s right by eye (terrain association) because it’s much quicker and flexible, and relies on the user understanding what they’re reading on the map, not just blindly following a bearing.

In short, there are two ways to orientate a map, depending on how accurate it needs to be:

By compass
By terrain association

Note, that the map does not need to be orientated to take a bearing from a map as the bearing is independent of the direction the map is pointing.

By Compass

Rest the map on level ground.
Rotate the compass bezel to set local magnetic declination (subtract 12.5° for Sydney, NSW area).
Place the compass on the map ensuring the grid lines are parallel with the edge of the compass, and that the top of the compass is pointing towards the top of the map.
Rotate the map and compass until the north (red) needle is sitting in the orientating arrow on the compass bezel.

Handy Tips

Remember that compasses work using a very weak magnetic force from the earth. If any objects with a stronger magnetic force are nearby they will distort the compass reading. Make sure that you are not near metal or power lines when using a compass. (e.g. never try using a compass on the hood of a car). Some regions of the earth have high iron content in their rocks making using a compass impossible. The easiest way of telling this is if the compass needle swings erratically, and never points consistently in the same direction, regardless of anything you do!
Generally, map orientation only needs to be accurate within a few degrees. Most of the time you can leave the compass with the magnetic variation set inside your map case and orientate the map whilst you are standing.

By Terrain Association
Terrain association is just matching the visible surroundings to the map. It is the most common method that bushwalkers use to orientate a map, but requires a good understanding of how to map read and translate features into real landforms. For this method to work, the user must know their approximate location.

Bushwalkers can determine map orientation by matching contours, comparing vegetation to that depicted on the map, constructed features (shapes of buildings, directions of roads) and hydrography (shape and size of lakes in conjunction with the size and direction of flow of the rivers and streams).

Handy Tip
Generally, bushwalkers use some combination of compass use and terrain association. Usually, they use the compass to get a rough idea of the lay of the land, then fine tune it by matching specific land features to the map. The best way to find out what works for you is to get out there and try!

Thumbing the map How to thumb the map to keep track of where you are

Switching the eyes from the map to the landscape and back again is tiring on the eyes and it’s easy to get disorientated and look at completely the wrong section of map (parallel error).

“Thumbing the map” is a technique used by bushwalkers to trace their location continuously onto the map. It means gripping the map between thumb and hand with the thumb at the exact location of the bushwalk and moving the thumb along the route as they move. In this way, bushwalkers can trace key waypoints {link to key waypoints chapter} as they occur, and know what’s coming up. This is far easier than having to figure out where they are on the map each time they stop.

Some walkers find that folding the map to a convenient size prevents damage and makes it easier to read. Many also use a map case to protect the map from getting damaged. Often map cases come with a neck-strap, allowing the user to carry it on their person and follow the map as they go.

Map Memory and Key Waypoints How to use map memory and key waypoints to stay found

Map memory is about memorizing key features or ‘waypoints’ on a map and ticking them off in your brain as you pass them. It’s about knowing what’s coming up, and if you don’t come across these features, then it quickly triggers a red flag. Think of map memory as ticking off a series of reliable key waypoints.

Key waypoints are those features that are in some way prominent or recognisable. Bushwalkers use key features to orient themselves, know where they are, how far they still have to go, and be able to navigate along the planned route. Memorising the next few waypoints allows the bushwalker to ‘put down the map’ so to speak, or rather at least enjoy the scenery for a bit rather than having their head constantly buried in the map.

A good guide is to memorise the next three major waypoints coming up, and mentally tick them off as you pass them. If anything happens that you weren’t expecting, then you can quickly fix it up. This mental mapping process means that you quickly know where your last ‘known’ point is, so when something doesn’t feel right you notice it straight away, rather than having to figure it out from scratch each time.

The best checkpoints are linear features that cross your route. Use streams, rivers, hard-top roads, ridges, valleys, and railroads, but be aware that some map features are more reliable than others. The next best checkpoints are elevation changes such as hills, depressions and spurs.

Chose waypoints are those that are easy to remember and obvious, but not so common that they are tricky to distinguish.

Examples include:

Land features like knolls, saddles, ridges. Generally very reliable (or as reliable as the data first collected to make the map).
Route features like river crossings. May be unreliable e.g. river crossings can be rainfall dependant.
Constructed features like junctions, road crossings. Again, may change over time or not be reliably marked on the map in the first place.

The number of reliable checkpoints along established on-track routes will vary, but aim to get at least one or two per kilometre. Once you start looking for this detail in the terrain, you’ll find it easier and easier to pick up. Suddenly a boring flat way has subtle ups and downs that you might not have otherwise noticed. Encourage everyone else in the group to keep a lookout for these checkpoints too.

GPS/smartphone devices Using GPS and smartphone devices as navigational tools

GPS devices and mobile smartphones allow the user to pinpoint their location to an accuracy of around 10-20m, often a much greater precision that by map and compass. They communicate with satellites and work well when they have a relatively clear view of the sky. They will not work in enclosed canyons, gorges and caves.

GPS technology allows the user to identify their physical location and plot it back to a topographic map. In a practical sense, often bushwalkers use a GPS to double check their location matches with where they think they are, or to identify recommended campsites, water locations, entrances to canyons, passes through cliff-lines, etc.

GPS users should make sure that their GPS is set to the right datum and projection, and that they understand how to translate the coordinates reported on a GPS unit onto a standard topographic map.

on-track navigation

Reliable and vague map features

BY Eva

What features to trust on the map and walk

When something on the map doesn’t match up with the physical landscape, the logical question “are I or the map right?” arises. Unfortunately, in most cases, the map is correct, and you’ve made an error at some point. However, it’s worth knowing that there are some features on maps that shouldn’t be trusted.

The most common features to change over time are constructed features: minor powerlines that no longer exist, gates that have been replaced, property boundaries that have moved, etc. Ways also evolve with time, and can easily change their course over time (i.e. since the geographic data used to make the map was collected). Therefore, if a constructed feature doesn’t match up with where you think you are on the map, don’t necessarily assume that you are wrong and the map is right. Focus on location identification using landscape features rather than just constructed ones, and if neither features match up with where you think you are on the map, then you’re probably not where you think you are.

Physical landscape features are far less likely to be wrong than constructed features. According to the ‘Australian Map and Spatial Data Horizontal Accuracy Standards’, the location accuracy of a map must be stated in terms of a percentage value of its true position. For example, the Sydney Heads 1:25,000 scale topographic map states “Horizontal accuracy is expected to be 90% of the well-defined detail within 12.5 m of its true position”.

Modern maps are made using a combination of on-ground geographical data and data from aerial imagery. The result is fairly reliable representations of the landscape. However, maps are only as accurate as their geographic data they are made with, and the historical notes of the surveyor. Aerial imagery, for example, can interpret wrong landform shapes if the tree line does not match the ground line. Hence topographic maps are susceptible to these sorts of errors, and can include features that are out of date or have changed, or are symbolized and named incorrectly.

BWRS has a current list of known map errors for NSW topographic maps and offers a service to report errors.

Reliable features, a rough guide More information about recognising reliable map features

To summarise, here is a rough guide for what features to trust from a topographic map:

GENERALLY TRUST

Land features (shape of land, creeks etc.)
Major constructed features (roads, major power lines (not minor ones)

GENERALLY DON’T TRUST

Signs and constructed features, building, houses, fences etc.)
Minor constructed ways: walking tracks, trails and paths can be drawn on the wrong side of a river, ridge, saddle etc.)

Vague features, a rough guide More information about recognising vague map features

Most on-track walking involves following a clear, pre-defined route, however, sometimes sections of the route are unclear, vague or damaged. Unclear routes can be tricky to navigate along, particularly if many people have made the same mistake and forged a new, incorrect, side tracks. Sometimes these tracks come to a dead end, other times they continue for kilometres, wasting valuable time, energy and patience of the group. Hence, it’s best to avoid these detours if at all possible. Maps may be missing information about extra tracks, trails and pathways also. Additional tracks or trails might also branch off from the main way but aren’t marked. If you follow these accidentally, stop and backtrack.

on-track navigation

Is this way right?

BY Eva

Some practical advice on finding and staying on the right way

Usually, the first sign that the way you’re going isn’t right is when it doesn’t match up with expected key waypoints. Remember that if enough bushwalkers make the same mistake, a new way will form. Very confusing!

Bushwalking ways are typically made by clearing vegetation, removing obstacles such as logs and compacting the soil or bringing in rocks etc. Common features to bushwalking ways include:

Cleared vegetation including cut logs (i.e. chainsawed trees)
Compacted soil or stones
Footprints
Signposts
Cairns (piles of rocks)

Ways that are faint or don’t include these features may not be right, and should start to raise alarm bells! Other signs that you’re not on the main way include:

The way leads to areas inaccessible to humans
The way weaves back upon itself
The way splits multiple times
The way leads off from the main route to a water source or shelter

The number one rule when things in the landscape don’t match with what you expect is to stop. Have a good think about where you last knew where you were, and return to that location. In doing so, you return to a spot where you are certain of the location on the map and can trace out where you went wrong. Most likely you missed a turn or there was a faint junction that you missed.

Picking up the way again How to find the way after losing it

Some bushwalking ways weave back and forth across rivers, cross large open rock platforms, or meander through urban villages before emerging on the other side and continuing. It’s easy to lose the way in these cases, as it’s not entirely clear where or how the way rejoins again. Here are a few tips to find the way again.

River crossings

Some bushwalking ways end at the river side, implying that the route crosses over and starts again directly on the other side.

Before crossing, double check that the way indeed crosses over, rather than continuing along the same river bank. Do this by having a quick scout around on the side of the bank you’re on, and looking over to the other side. Sometimes, there’s a clear sign where the way starts again, or there’s a signpost, a small arrow, or a marker. Don’t be surprised though if the way only becomes visible once you’re on the other side: many river crossings are implied rather than signposted.

Assess if the river is safe to cross. Then choose where to cross the river, bearing in mind that this might involve detouring slightly upstream or downstream of the path. Then continue along the way again.

If you cannot pick up the way again after the river crossing, cross back to the way you were on and go back to the last known point. You may have accidentally strayed from the main way, or picked up a way leading off the main one to the river (typical for lunch or swimming spots).

Maps are not that reliable when it comes to river crossings. Ways change over time, and where the way originally crossed the river, it may not do so any more.

The best general advice is to follow the main way whenever given a choice. That is, if the main way continues on one side of the river and you spot another smaller way on the other side of the river, then don’t cross over, stick to the main one. Conversely, if the main way continues on the other side of the river, and only a minor one follows on the same side, cross over.

Townships

Walks often pass through small urban towns when going from one section of bush to another. It is particularly common on multiday trips, for example, the Great North Walk.

As ironic as it sounds, it can be quite easy to lose the way through a township due to poor signage, or changes to the route due to development. Often the way may disappear at one edge of the town, and bushwalkers need to pick it up at the other side, but it’s not always entirely clear where to do it. Remember that maps may not have up to date information on housing development, particularly on the edges of urban townships. Hence, it can be embarrassingly easy to miss where the way starts again in an urban area!

The good news is that it’s usually pretty straightforward to figure it out. If the way doesn’t have obvious signposts, why not try dropping into the local cafe and chatting to the owners? Most locals are keen to talk about their local bushwalks, and they can probably give you some great advice on where to pick up the way again. Be sensitive to ways that pass through private properties and make sure to ask permission before using them.

In this day and age, modern townships usually mean reasonable mobile phone reception. Google maps may provide useful satellite data on where bushwalking ways start and stop. Even tourist websites and blogs can help.

Failing all that, you can usually work out where the way goes by a process of elimination: if the way comes into the township from the south, it’s going to leave via the North, East or West side. If there’s major bushland on the northern part of the township, then that’s a good place to start scouting out for the way. Roads that are dead ends onto bushland are likely candidates for where the way continues.

Being lost in a township can be quite an enjoyable experience, particularly if there’s a nice place to stop for ice-cream en-route!

Rock platforms

Bushwalking tracks will often cross rock platforms, large open slabs of rock with a small amount of vegetation growing between the rock cracks. From a trackmaker’s point of view, including a section of rock is much less work than having to lug in rocks or create a track themselves. It takes little work to maintain and is easy walking for visitors. The downside is that most rock platforms are around 10-20m wide and bushwalkers have to find the track again on the other side. Putting signs on every single rock platform is impractical, so bushwalkers are usually left to locate the track on their own.

In general, a track that goes in on one side of the rock platform forms again on the opposite side of the platform…but not always! On rock platforms where the track continuation is ambiguous, many smaller tracks form where bushwalkers have thought the track continues. This is a big problem for local wildlife and plants due to soil erosion and compaction damage.

Best practice is to avoid using smaller side tracks to scout out the main track. Stay on the rock platform until it’s clear your group has found the correct track. If the track turns out to be wrong, backtrack until you know where you are again.

Rock platforms make for easy walking compared to rough scrub, but be sensitive towards delicate rock formations. Around Sydney, the sandstone pagoda country is stunningly beautiful but extraordinarily delicate. Rock pagodas formed over millennia are easily broken by careless bushwalkers stepping on their edges. Tread lightly and Leave No Trace!

Sandy areas

Coastal walks often involve walking in parts along beaches. It’s a great opportunity to take your shoes off and feel the sand on your feet. Finding the way again is usually pretty straightforward, but the way may not be well signposted, or the signs only works well if you’re walking in a particular direction.

A typical setup is where the way joins at one end of the beach and leaves at the other end.

A few variations on this include:

The route continues next to beach, and joins beach halfway along.
The route leaves beach halfway along.
The route never joins beach.

Once again, a map of the route may not be a reliable guide to where the route goes. Routes along beaches may change with tides, or be hidden by shifting sand. It can be worth contacting local land rangers to ask about the current condition of the route first.

Leave no Trace by walking on the hard sand nearest the ocean and avoid walking on delicate sand dunes as much as possible. Spread out to even out footprints on the sand.

What do I do if I’m lost? Finding yourself again, a practical guide

It can be a frightening experience to feel lost in the bush, even if that feeling is momentary. It’s a reminder of how very small humans are in the world, and how much unknown landscape there is.

Finding the way again when you’re lost is all about remaining calm, staying logical and keeping a clear head despite every other emotion you’re feeling. It’s about everyone in the group contributing to the navigation decisions and backtracking to the last known place.

The biggest mistake a bushwalking group can make it to press on further. It’s tempting just to check what’s around the next corner, maybe there’s a sign there, maybe another track…? The reality is, going further onwards will almost always make things worse, not better! While it may feel like a waste of time and energy, stopping and backtracking means that you can reaffirm exactly where you are and if you went wrong.

Here’s a general set of guidelines to follow if you don’t know where you are:

Stop. Go through a deductive and logical reasoning process to figure out where you are from the last known point. Ask questions like:
1. Did we cross a creek? Is the creek flowing the direction it should be?
2. Did we climb a hill? Was it smaller or larger than expected?
3. What direction are we going in? Does this make sense?
4. Did we pass any forks?
5. How fast are we traveling? What’s the furthest we can be from the last known point
Use navigation tools, like a GPS or compass to help.
Most of the time, this is enough to help you figure out where you are. Most often, it’s because you’re moving slower than you expected, or took a wrong turning.
If you cannot determine your location through a deductive and logical reasoning process:
Backtrack to the last known point.
After backtracking, you’ll probably figure out where you went wrong in the first place and can continue along the correct way.
If you cannot backtrack to the last known point (e.g. poor weather conditions, visibility).
Stop. Consider waiting until weather conditions improve.
If you are completely lost and have exhausted all other means of finding yourself, contact the emergency services by telephone (if reception) or activating a PLB.