Unit 1 was traveling South on the Keowee River section of Lake Hartwell near Issaqueena dam when it encountered a large wake from another boat. 

After cresting the wake, the nose of unit 1 went under the water, causing unit 1 to flood and capsize. After all occupants were found to be safe and accounted for, good Samaritans helped Unit 1 to right the boat and another Good Samaritan towed unit 1 back to the boat ramp. No witnesses were able to give a description of the boat that caused the large wake.
Lake Hartwell