RedactedNarrative: I was dispatched to a boat that was dead in the water on at approx 1745 hours at Sand Hollow Reservoir.  Once I left the marina I noticed a boat uncommonly close to the north dam rocks and assumed that was the boat I was looking for.  
  
  I made contact with the boat and noticed two females in the boat and a male attempting to hold the boat away from the rocks.  I pulled up and threw them a rope to secure to their boat.  At that time I noticed a second male at the stern of the boat.  As I pulled them away I noticed a male lying in the front of the boat and a female holding his ankle.  I used the PA to ask if he was injured.  I could only communicate with yes and no questions and was under the impression of a crushing injury but nothing broken.  I asked medical to meet me at the dock.
  
  I arrived at the dock and tied their boat off.  Medical arrived and cleared the injury victim with a laceration to the rear of his ankle from a rock rolling onto it at the dam.
  
  A follow up call to the injury victim gave the details that they were operating the boat and underway on the lake when the boat died.  He could not get it started again.  On the phone call he said the boat had had troubles like that before possibly with the carburetor.  He said they had been against the rocks about 5-10 minutes before I arrived.
  
  