Sorry I've been away so long. Here's the note from Andy's book (by the way it has 60 of his songs - some originals, some traditional and I'd highly recommend it).

The Loch Tay Boat Song:(Iorram Loch Tatha). The melody was collected from a Mrs. Cameron at Inverailort, in the district of Moidart, in 1870. The words are by Harold Boulton, a writier and translator of songs in the Gaelic language. Boulton edited the weighty, three volume, "Songs of The North", (1885-1926) in which this song first appears. It was fellow Perthshire man and friend since High School, Dougie Maclean, who I first heard singing this song.

Cheers, Rick