May 2021 - Beginner's Guide to Navigation - Choosing a map

by Nigel Williams

There are a variety of maps available. Even using a street map in an urban area can be a great starting point. Most maps use similar symbols which are quite intuitive, and the map should have a key or legend on it so there is no need to memorise them.

There is a balance between the detail on a map, how large an area it covers and cost. There are 3 main scales used in the UK, and all these maps, regardless of the scale, have grid squares which measure the ground 1km across or 1.5km diagonally.

1:25,000 scale (4cms on the map = 1km on the ground or 4mm = 100m) is used by HARVEY Maps and Ordnance Survey (OS). This is the best scale for the novice as it has a lot more detailed information which helps build confidence and trust with the map. This scale includes field boundaries, some underfoot conditions such as marshy ground and rough grassland, as well as visitor and access information. However, these maps cover a much smaller area compared to the other commonly used scales, generally around 460 square kms per map sheet.

A 1:50,000 (2cms = 1km or 2mm = 100m) an OS map has less detail requiring a greater ability of interpretation of what you see around you, but it generally covers 1,600 square km. Probably the most important symbols for a walker are footpaths, black dashed lines, but be aware of slightly smaller dashed lines usually around woods or beside a road which indicate that they are unfenced, it is not a path.

So many DofE award expeditions have been caught out by those dashed lines. Rough vehicle tracks such as forest and hill tracks show two parallel small dashed lines indicating the route is unfenced on both sides. Find a footpath and a track close to each other on a map and the difference will be obvious.

HARVEY maps use a 1:40,000 scale (2.5cms = 1km or 2.5mm =100m) which allows for a great combination of detail and area covered, sometimes referred to as the "magic scale". The map contains 1:25,000 detail whilst covering around 1,370 square km per sheet. It also uses colour shading to help appreciate elevation and makes for a generally more aesthetic map. They are also very tough, lightweight and 100% waterproof. They don't cover the whole of the UK, but focus on upland areas and National Trails from the South Downs to the far north of Scotland.

Keep paper maps waterproof in a clear bag or map case folded to the area you need (removing the cardboard outer helps). Careful preparation of the map enables it to be kept to hand so it can be referred to quickly and easily. Avoid having to open out a full map on a wet and windy day.

Scanning the section of map to make an A4 copy for personal use which can fit in a map case more easily may be possible but has limitations, such as no key being available. People who struggle with reading glasses sometime copy and enlarge sections of map to make it easier to read.

Lastly, have the compass handy in a pocket (well away from your mobile phone as the magnet in the speaker can cause significant and permanent problems for the magnetic needle).




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