Jim-

"some nautical types think it refers to the practice by victims of a sinking ship to look for any flotsam, such as a chicken-coop or hatch cover, to help keep them afloat until rescue."

I was seriously addressing your question, and there are many examples in the nautical literature to back up my answer, in addition to Punch Magazine.

Weelittledrummer-

Well, I hadn't considered that but let me ponder!

Charley Noble