RedactedNarrative: UNIT 1 STATED THAT WHILE TRAVELING SOUTH, HIS PASSENGER ALERTED HIM TO UNIT 2.  UNIT 1 TURNED HARD TO PORT COLLIDING WITH UNIT 2 ON THE STARBOARD.  UNIT 2 WAS TRAVELING NORTH AND HE DID NOT SEE UNIT 1 UNTIL HIS PASSENGER ALERTED HIM.  UNIT 2 ALSO TURNED TO PORT PRIOR TO THE COLLISION.