Royal Observer Corps Long Service Medal Service_Army it was extended to officers it was extended to officers of the RAF for acts of gallantry on the ground and during World War One there was provision made for officers of the Royal Naval Division and Royal Marines marking the end of a distinguished chapter in Commonwealth military aviation history The ribbon represents the pale blue of the daytime sky with the dark blue of the night sky being but by the silver of a searchlight beam It was awarded to part time officers and observers who had completed 12 years service and full time officers and observers who had completed 24 years service