 FACT: When Ernest Borgnine is piloting his tug and approaching the  Vega, he signals the Vega with three short blasts on the horn.  According to US Coast Guard Navigation Rule 34, three short blasts  on the horn indicates "I am operating astern propulsion" (backing  up). He is obviously going forward and should have sounded 1 short  blast to indicate "I intend to leave you on my port side", 2 short  blasts to indicate "I intend to leave you on my starboard side" or  the danger signal, which is 5 short blasts, if the other vessel was  not following the navigation rules.