'Folk etymology'

There is an expression that originated in transatlantic ocean travel relating to the best side of the ship to travel on. What is that phrase?

You may be thinking of the posh (Port Out Starboard Home) myth, one of many folk etymologies that people love to parade around on leashes. See www.phrases.org.uk meanings 287800.html

Strictly speaking, this is not folk etymology. Folk etymology is the changing of a word to reflect other familiar words or elements of words. For example, 'cucaracha' becomes 'cockroach'.