One Ping Only

I have a few little sayings that I like to quote.  I don't use them all of the time but they come in handy every once in a while.  One of these little phrases is, "One Ping Only".  Many of you may not know what movie that is from.  It is from "The Hunt for Red October".  It is a very important part of the movie that makes or breaks the fate of a submarine crew.  I decided to try and track it down for those of you that have heard me use the phrase.  Enjoy.