On the up/down direction question, a snippet gleaned from a colleague a few weeks ago. He was an east coast fisherman (UK) until a few years ago and we now run pleasure trips out of the same port. I'm writing from memory here, so it isn't a direct quote, but it is certainly the sense of what he was saying.

The Tyne and Scotland was always 'down', and the Humber or London way was always 'up'. It sounds wrong if you look at a map, but that's what we said, I don't know why.

I have since confirmed it with another (older) colleague who has spent some 60 years among the small craft up and down the east and south coasts. He too had no explanation, but confirmed the usage as being the same at least as far as the Thames.

Of course these are 20th century references, but it is hard to envisage such customs suddenly having turned 180 degrees without it being noticed. Whoever added the chorus appears to have been familiar with local custom.