RedactedNarrative: Operator` was the operator of vessel A.  Occupant1 was the passenger and acting as the spotter for Victim who was riding a wake board.  There was a red flag on board as required when towing a water skier.  Victim lost her balance while wake boarding and fell to her left.  Victim left knee hit the water.  The impact of the water dislocated her left knee cap pushing it to the outside of the knee.  While waiting for emergency responders, the knee cap was pushed back in to place.  Los Pinos EMS was requested to meet at the Arboles (Colorado) State park boat dock to provide care for Victim.  Operator` drove his vessel to Arboles with Victim and Occupant1 on board.  Victim was evaluated by EMS personnel and declined any furhter services as she found she could walk despite her injury.  No other vessels were involved. All occupants were observed to be wearing their Type III PFD's.