I would agree with those who have said that it comes down to personal attitude and intent, both in the singer and the audience. "Prats" are not confined to folk clubs, or teaching, and not even to Australia,(a lot of Kiwis would argue the last point). As Kris has pointed out, there is a world of difference between a comment on a particular version of a song, and a pontification of correctness. Similarly I would agree that one should not intentionally set out to offend and I would omit verse or songs in a particular venue if I thought this likely, but certainly not to the extent of destroying the meaning of the song in its original context. If in doubt I find that an explanation of the origin and that the song represents a particular time and place defuses any potential problem.

I suppose my reaction to Bill@Oz's protagonist would be to point out, in a politically correct way of course, that although his identification of the taxonomy of cetacea was correct, his knowledge of etymology and ethnology was sadly lacking!

The thing I find most fascinating about this thread is the variation in what is considered "acceptable" with locality.

I was particularly struck by the lyrics which Roger felt unable to sing outside his house. This seems to me to be an updated version of Hanging Johnny, which is generally one of the most popular of the shanties I inflict on trainees when sailing.

Incidentally Tim, the Tin Pan Alley version of "Barnacle Bill the sailor" is a cleaned up version of older songs not the other way round. (For example "Abraham the sailor" published in Tawney's Grey Funnel lines.)

There's nowt so queer as folk, as they say.

Pete M