The swimming test was the method of justice used in the Horninghold 'trials'. This was claimed to use divine intervention to decide the guilt of the accused, in that God's water would reject a witch causing them to float. At Horninghold it was used as a form of mob justice to punish the victims, probably as a form of 'entertainment'.

This image is taken from a 1613 pamphlet covering the trial of Mother Sutton and Mary Sutton of Bedfordshire. It is one of the earliest and best depictions of the test.