Islands of Ireland: Eyrie story from Crump Island

It is probably the strangest method ever devised for establishing a sea border anywhere in the world. In the mists of time in attempting to decide the borders between the counties of Galway and Mayo the good burghers decided that the best way to mark the border was by throwing a sack of oats into the sea and seeing where it would come to rest. The incident is recorded in the sea-kayakers bible Oileáin by David Walsh.
“The islands that lay to the N of the oats as they floated out would be in Mayo those to the S in Galway. To the surprise of many it floated down S of Crump and then headed out to sea,” he writes.