We were singing "Bully in the Alley" to help introduce nautical writer James Nelson at a bookstore signing. The chorus is supposed to run:

So help me, Bob, I'm bully in the alley!

And I burst forth with:

So help me, GOD, I'm bully in the alley!

Reducing my shanty chorus mates to either hysterical giggles or slack-jawed shock.

Oh, well, that's what the original line probably meant in dockside rhyming slang.