Great Britain Map for Garmin Mapping devices
Based on OS Mapping :-
Every Road
Every Stream
Every Wood and Copse
Every Building
Land features : rocks, cuttings, embankments
Contours
Most Rights of way
Tracks and footpaths
View, Plan and Print with Garmin Basecamp
   and more
Updated June2018 with 2018 OS and OSM data; also rights of way from Cumbria, Powys, Carmarthen, Northamtonshire, North Yorkshire        
Garmin users in Britain have had to choose between Ordnance Survey detail at high prices or maps based on Open Street Map (as Garmin's Topo Lite is) which, in many areas, lack the topographical detail for safe navigation in open country.

When the Ordnance Survey  released its Opendata product in 2010 it was a great advance but still lacking in quality compared to Landranger and Explorer products. I have merged Opendata District Vector data with OS contour data and footpath data from Open Street Map and Rights of Way data from Local Authorities (where available) to make a map in Garmin-compatible GMAP format for Garmin devices that can use it.

This map is available at a price of 20 download.  The maps have more topographical detail than Garmin Topo Lite and are a fraction of the price of OS maps of comparable detail. See here for some detailed comparisons. Note the level of topographical detail : streams, woods, buildings and rocks. The map can be used in Basecamp (with or without a Garmin device attached) for viewing, printing and route planning - and downlaoded to any of the devices that support IMG maps.

The mapping covers the whole of England, Scotland and Wales but not Northern Ireland nor the Irish Republic. The Isle of Man and Channel Islands are not included. The map is in one section. The download size is ~650MB. In accordance with Open Street Map rules, the maps will not be locked. You can use them on any device you have but they are not for redistribution nor onward sale. The maps are designed for hikers and bikers : they are not routable and concentrate on the geographic information with a few points of interest. Contour lines are drawn from the OS Terrain 50 product but these are not seen by Basecamp or Garmin Devices as a Digital Elevation Model.
 
Please click here to download sample map (7.9Mb) of the Peak District. Unzip the file. On Windows, copy the .gmap file to C:\ProgramData\Garmin\Maps\ ; on Mac open the .gmap file with Garmin’s MapManager.
[On some Windows systems, Basecamp will not find the file in ProgramData; an alternative place to copy is C:\Program Files(x86)\Garmin\Basecamp\Maps\]
Below is an extract of the image in Basecamp. Rights of Way are shown in green (dotted for footpaths, dashed for bridleways); restricted roads ('BOATs') are shown in mauve; other paths from Open Street Map are shown in red. Rights of Way details are available for most of England and Wales (see www.rowmaps.com for details - and many thanks to Barry Cornelius for the data) but not for Scotland (where the law is different). Where no Rights of Way data is available all paths are from Open Street Map and shown in red. Also from Open Street Map are selected points of interest and routes of abandoned railways. There is a full key here.

This file is in GMAP format ; if you are unable to run Basecamp (e.g Linux users) or just want a .IMG file for applications such as QMAPSHACK then click here.

Please Email if you have any queries or comments.  There are some technical details here.

Please be aware that the latest (4.7) version of Basecamp may not install this map - workaround details are here

Click here to buy.

Although these maps are designed for Garmin units (whose trademarks are acknowledged) they are not endorsed by Garmin.These maps use OS Opendata but are not endoresed nor recommended by the OS
Peak district extract
Contains Ordnance Survey data Crown copyright and database right 2011,2018;
OpenStreetMap contributors under Open Database Licence
Rights of way data from selected Local Authorities under Open Government Licence  : see www.rowmaps.com