It's a keeper, all right. Good work, Charlie. I'm going to copy this and add it to my archives.

One thought - perhaps that should be 'south with the trades' in line 6. I believe I have heard the trade winds referred to as 'the trades.'

For any Americans interested, Charley's tune is based on what we know as 'Sweet Betsy from Pike.'

(I never would have gussed that Rotherhithe is pronounced the way you've pronounced it.)