When you are using the Garmin Ordnance Survey 1:25k Map cards covering all of Great Britain to plan Routes with in BaseCamp you can only select one of the 5 map areas at a time to view on the map page i.e. East England, North England & IOM, North Scotland, South Scotland & West England & Wales, you cannot view all of the areas together only one at a time.

If you are planning a Route that moves across different regions you can select the different map sets as they are needed from the Map menu along the top menu options in BaseCamp software.

Video instructions and top tips for everything you need to know about Garmin BaseCamp can be found in the GPS Training online resource - more here