RedactedNarrative: On July 27, 2014, at approximately 1117 hours, Lake Mead National Recreation Area Interagency Communications Center (LMICC) received a call from an employee at Willow Beach Marina.  The employee stated there was an individual at the launch ramp that needed emergency medical assistance.  Our investigation revealed an Eliminator vessel had been cruising southbound near river mile 53 on Lake Mohave when the operator slowed down and came off plane.  The operator of the personal watercraft (PWC) was following the Eliminator vessel and could not stop in time to avoid collision.  The PWC ran up the stern of the Eliminator vessel, hit an occupant in the back who was standing on the Eliminator vessel, and came to rest on top of the engine hatch of the Eliminator vessel.  After the accident, the patient was transported by the Eliminator vessel back to Willow Beach Marina.  The patient was flown by TriState Careflight to University Medical Center.  Operator2 was issued a collateral citation for reckless vessel operations.