RedactedNarrative: On Friday, May 24, 2013, at approximately 2:50 pm, I, Officer, responded to a injury accident call.  I arrived at Hemenway Launch Ramp where National Park Service was treating an injured person.  The person was complaining of an injured/ dislocated right shoulder.  The subject was transported by ambulance to a local hospital where he was admitted and treated for the dislocated shoulder.
  Based on statements, subject  operated one of two pontoon boats rented from Las Vegas Harbor on Lake Mead to Black Canyon.  At approximately 2:20pm vessel was turned off and then some of the occupants entered the water to swim.  At around 2:30, subject2 jumped into the water and dislocated his right shoulder.
  No one onboard or in the water observed subject2 leave the boat but heard the screams of pain from subject2 when he surfaced from the water.  Several boat occupants assisted him onto the boat and then the vessel was operated to Hemenway Launch Ramp where Park Service provided medical.
  No vessel damage was reported.
  No property damage was reported.
NameOfBodyOfWater: Lake Mead
NearestCityTown: Boulder City