I've had the above question asked of me before, and received an e-mail with this question tonight.
Thought I'd pose it here too. Does anyone know of a version of it in Gaelic?

As far as I can TELL, the Skye Boat Song was written in the mid-1800s to an old Gaelic air. I have found that that air MIGHT be Cuachag Nan Craobh. This is a song written by William Ross from the late 17th century, which translates as Cuckoo of the Grove. However, the tune is reversed - The first four lines are sung to the second half of Skye Boat Song, and the tune of the second half of Cuachag Nan Craobh is that of the first half of Skye. Or it is VERY nearly so. (I don't read music, but my friends who do say that is the case).

Besides that, I have come across a copy of a recording by Rhona NicLeo\id (Rhona MacLeod), who sings a song called Siubhail A Bhirlinn, which is sung to the Skye Boat Song tune. HOWEVER I have been unable to make out the words to the song, and have not located the words. The title doesn't translate to that of the Skye Boat Song. Can anyone suggest a source for those lyrics?

For the words to Cuachag Nan Craobh