Rockall is actually off the edge of the Ordnance Survey of Great Britain
(OSGB) mapping grid, and appears as an inset on Landranger sheet 18.
If you extend the grid westwards, Rockall is in 100km grid MC:
10km x 10km OSGB Grid MC01
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.