RedactedNarrative: On September 3, 2017 at approximately 15:22 hrs. Lake Mead Rangers recieved a report of a male with a shoulder injury at the Calville Courtesy Dock. Rangers responded and found the patient in the boat rentals office of Calville Bay Marina. One 26 year old male was identified as the patient and was reported to be being towed behind a 20'' Ski Centron Boat with Nevada Registration. The patient fell off of the knee board while being towed and sustained an injury. The boat then brought the patient into Calville Bay Marina for treatment.  No damage to the boat was reported. 4 people were on board the boat at the time of the injury and the patient was being towed on a knee board.