Rockall is actually off the edge of the Ordnance Survey of Great Britain
(OSGB) mapping grid. If you extend the grid westwards, Rockall is in 100km grid MC:
100km x 100km OSGB Grid MC
Image should be printed 24cm wide (20cm x 20cm map) for correct scale.
Image should be printed 24cm wide (20cm x 20cm map) for correct scale.