Not a Barrel of Fun

I wondered why people say “over a barrel”
For being quite helpless and likely in peril.
My sources have cited two actions at sea.
They’re both rather grim—not surprising to me.
It’s said that a sailor who nearly was drowned
Got draped on a barrel until he came ‘round
From having his lungs cleared of water at last,
Or else, in our late 19th-century past,
The barrel was where one got held down or strapped
For flogging. I must say the image is apt,
But sources keep showing the very same pic
Of a man with a paddle about to give licks
To a man on a barrel who’s wearing just shorts.
I doubt it was common with so few reports.
For my part, I hope that the first story’s true.
If not, well, the phrase is still fine in my view.