RedactedNarrative: On 5/15/14 at about 11:00 hours, operator was operating his 1997 Donzi BTW on Canyon Lake in the area of Sandy Beach. Operator1 had driven upstream past the buoy line warning boaters of "Unmarked Hazards". Operator1 continued past the buoys and around a curve in the lake. Operator1 stated he moved right to avoid a boat and subsequently struck a submerged rock. After striking the rock, Operator1s boat began to take on water. Operator1 was able to get the boat back to shallow water near Sandy Beach, where the boat became partially submerged. 
  
  Upon my arrival to the scene, I located the boat on the east end of Sandy Beach. I could see the transom of the boat was completely submerged. The bow of the boat was out of the water, with the tip of the bow about eight feet above the surface of the water. Due to the fact that the transom was submerged, I was not able to visually see what damage kind of damage the hull had sustained. It is unknown if the lower unit or propeller were damaged in the accident. 
  
  Upon contacting Operator1, who was the operator and his passenger, I discovered neither of them were injured and did not require any medical attention. 
  
  Due to the fact that the watercraft was submerged and would need specialized equipment to recover it, I secured a bow-line to a tree. I then transported subjects back to the MCSO Canyon Lake aid station where they were subsequently released to begin making recovery arrangements. 
  
  No citations were issued, due to the fact that the object that was struck was an unmarked submerged rock. 
  
  This report was taken for documentation purposes only. 
  
  Nothing further