A tip of the hat is necessary to John Piña Craven (deceased), the Chief Scientist of the US Navy Special Project Office at the time.

He made mention of his days on the Mississippi River and the occasional "Underwater cable - Do not drag anchor" signs that dot the riverside. When asked, "What? You mean we should look for signs that say 'Underwater cable - Do not drag anchor' written in Russian?"

His answer was pretty much "Yes, that's exactly what we should do."

Craven was a colorful character and worth anyone's time to look up more on his contributions. I'll second the recommendation to the book "Blind Man's Bluff."