Music Boulevard lists 15 versions here~~

http://mb1.musicblvd.com/cgi-bin/tw?SID=134926866199403&MT=41&STORE=all&limit=100&search_term=skye+boat&search_type=song&x=36&y=16

Six of the seven versions that have realaudio listed have the song available for listening, but none of them play long enough to tell if there are vocals or not.

Incidently, if that URL is not a case for copy and paste, I don't know what is.