"mal-de-mer" -- I think I got the spelling right. It means sea-sickness. I can't remember what His Lordship had advised as a cure -- probably the lash.

IIRC, the chorus also has a play on the word "oar" -- remember it would have been English sailors singing the song.

"Hoarse weasel" -- a mondegreen for the title of a nasty Nazi song, which seems to have a tune suitable for an Anglican hymn? (See previous thread on subject.)