Just to add a bit of trivia to this mythic song - MacColl not only studied Larner's speech (and his life history) in search of accuracy...he also did so with the rest of the song.

He pinned a huge map of the North Sea on his bedroom wall. As he wrote, he would run into the bedroom and consult the map. This ensured for him the place names and possible routes for the trips. Much of the progress of the song's subject is taken directly from Larner's life.

That "Shores of Erin" reference is slightly off. It was possibly a single incident, not that the song was generally or even widely known by that. It seems to spring from a comment, apparently by MacColl and both Palmer (Oxford Book of Sea Songs) and "freeborn man" LP, note it's been collected in Ireland as "The Shores of Erin." I've never seen any corrorboration of that until just now reading Dave Bryant's comment above. But I'd still really like to see a certain reference and text. Maybe it's just the whistle tune mentioned by curmudgeon.

Last, I believe this to be a great example of a true "folk song." Or "Neo-folk song." That is, one that is recent, transmitted in part electronically and of known authorship but... Passes in the community of folksingers oraly and rapidly and "processes" as it goes. It was recorded early on (and in significantly differing versions) by the likes of Killen, Kelly, Makem, the Corries and even MacColl. (MacColl because he kept changing it and in the Radio show, he is not the sole singer of the song.) It even enters the literature as early as 1965 by no less than Palmer.