RedactedNarrative: Driver of PWC advised she did not remember what happened just prior to the crash.  Boyfriend of driver advised how was on shore with vehicle and trailer and driver was riding PWC by access.  Boyfriend stated he heard PWC and then saw Operator flying up onto beach and landing on beach hitting tree.  Boyfriend stated he believes that Operator hit low hanging branch, knocking her off PWC.  Operator was transported via life flight to Saginaw St. Mary's with a brain bleed head injury.  She was not wearing a life jacket.  The vessel was not damaged.