I have a recording of Matt MacIsaac playing Boys of the Lough. It’s track 8 on this CD, and there is a clip you can hear:
http://bagpipediscs.com/catalog/product_info.php?products_id=1199&osCsid=vaau6np4a5k44ffl6gusckvjk6
I’m trying to figure out what key his whistle is. He’s playing at least three sharps or flats, depending on how you call them – C#, A#, and F# (or Db, Bb, and Gb) are all present in the first bar (concert pitch, not fingerings).