Unit 1 was traveling up lake Marion (north west)towards I95 bridge coming from Mill Creek direction and struck a channel marker. Damage was to the front post side of boat. This accident occurred on 09/20/2013, Officer was notified about the boating accident on 9/23/2013 by 1st SGT . Officer  located the vessel at Johnson's Marine in Orangeburg SC on 9/23/2013. Officer  took pictures of the boat, registration number SC2648BV, and checked the vessel for all safety equipment or any evidence. The vessel had all the required safety equipment. Officer  then contacted the operator and owner of the vessel, and interviewed him. operator states he and 5 other people traveling up Lake Marion towards I95 bridge when he struck a channel marker. operator states it was channel marker 81, 82, or 83, e was unsure of the number. operator stated as he was traveling when he saw the marker at the last minute so he turned right but still hit the marker on his port side. Out of the 6 people aboard, 3 were injured including himself operator suffered a stomach injury. victim1 suffered a cut on his lip which resulted in 5 stitches. victim2 suffered a head injury which resulted in 4 stitches in the back of her head. All were treated at TRM and released. operator stated his vessel made it back to the landing without any assistance. operator said the channel marker was not visible due to darkness. As of this date Officer  has not heard about any damages to any markers. After Officer  investigation no citations were issued.