It's the chorus that lingers:

Paddy lay back, (Paddy lay back)
Take in your slack (take in your slack)
Take a turn around the capstan heave and hawl (?)
About ship station, boys, be handy (be handy!)
For we're bound for Valparaiso ‘round the horn

Where? North east / west UK singarounds
When? 1975-2012.
Who? A lot of much missed & dearly departed old friends.

What led me to ask? Because you holler along in good drunken faith without giving too much thought to provenance then decades later it pops into your brain (one of the truly miraculous creations in the universe?) out of nowhere and it gets you thinking.