Extremely interesting. I was a Guide in Scotland in the late 60s/early 70s but never came across this song. The dying child story with so many diverse versions suggests a folk myth, like the origin of 'Ring a ring of roses' (nothing to do with the plague) or Loch Lomond (no evidence of Jacobite prisoners who fit the story). What also strikes me is that barges, as a rule, do not sail across the oceans! But doubtless it's a good song.

I liked the 'Guide Marching Song' which I see has had a new verse written for the centenary. A nice, jolly little ditty,