I'm a shanteyman from "Down Under" and have been singing "Down Trinidad" for years. Once you understand that "Sonny Daw" in sailors rhyming slang means "Whore" the chorus makes perfect sense. I sing "Boots free me Bully Boys unbuttoned in the alley. i.e Jack Tar is visiting a brothel (maybe Madame Gashees) and is taking off his sea boots in the alley outside in anticiption!