RedactedNarrative: On July 5, 2015, at approximately 1532 Hrs, operator of sole vessel involved in incident was being bothered by a bee.  She left the operator's chair and began to swat at the bee with a towel, leaving the vessel's controls unattended.  The vessel was traveling approximately 15 miles per hour when it struck a tree on the bank, damaging the bow and starboard side of vessel.  Operator fell forward during the collision, striking her head on the gate leading to the bow swim deck.  Damage to gate was consistent with an occupant inside vessel falling into it, as the gate was bent outward.  Operator sustained a severe laceration to her head the required stitches and also complained of minor injuries to her left wrist and right ankle.  A second occupant was uninjured and provided statements corroborating operator's summary of the event.