RedactedNarrative: OPERATOR OF V1 WAS FISHING BY TROLLING WHEN MOTOR MALFUNCTIONED CAUSING V1 TO HIT V2 PORT BOW AND CAUSE DAMAGE.  V2 WAS AT DOCK AND UNOCCUPIED AT TIME.  UNKNOWN WHY MOTOR MALFUNCTIONED. PFD WERE ON AND USED ON V1. ALCOHOL WAS NOT A FACTOR.