RedactedNarrative: UNIT 1 BACKED UP AND WENT FORWARD AFTER PUTTING IN THE WATER.  UNIT 1 STRUCK THE MOTOR COWLING OF UNIT 2 CAUSING DAMAGE TO THE THROTTLE CONTROLS OF UNIT 2.  OPERATOR OF UNIT 2 SHIFTED TO REVERSE AND IT WENT FULL THROTTLE.  OPERATOR OF UNIT 2 THEN SHIFTED TO FORWARD AND IT WENT FULL THROTTLE.  UNIT 2 WENT OVER THE DOCK AND STRUCK UNIT 3, WHICH WAS DOCKED AND UNOCCUPIED.