Operator was operating vessel, near the Ritz Carlton Lodge, when he felt a big thump. Operator stated as he throttled down the vessel to check the damage, he could not physically see anything. Operator stated he swam the vessel over to the Ritz Carlton's lodge for assistance. As I met Operator at South Bay Marina, I observed extensive damage to the vessel's outdrive housing, prop, and skeg. Operator showed me the area in which the object was struck. As I searched the area intensively for a potential floating object, non was observed. Standing timbers were the only objects observed in the impact area. Operator operated the vessel too close to the standing timber failing to keep a proper lookout of being familiar with this area of the lake. As I inspected the Sea Ray's prop, the main damage was consistent with that of a hard fixed object (such as a rock or concrete). I located fine pieces of wood found in the jagged breaks of the prop which would be consistent of a soft strike. It appeared that some of the boat's damages were pre existing prior to striking the standing timber. Operator stated he failed to perform a pretrip inspection of the lower unit of the vessel.
Greensboro                    