Abstract
The story of St. Columba's supposed encounter with an aquatic beast, contained in Adomnan's Life of the saint, is critically examined and placed in historical context. Its cryptozoological relevance should be discounted. An actual event of ca. 580 A.D., reported from oral tradition 110 years later, can be postulated, but it would have been no more than the disturbance of some large, stray marine mammal in the River Ness, apparently at a ferry crossing near the Moray Firth river-mouth.