RedactedNarrative: On 06/16/2017 at approx. 21:59 CST, I received a call from KSP Post 3 about a boat accident on Nolin Lake.  The dispatcher advised that no one was injured in the accident, but that it involved one of their officers and they provided me with his contact info.  I contacted the officer (Operator2) and he advised that both vessels and all persons involved were at the Nolin Sate Park Boat Ramp.  
       I arrived at the boat ramp at approx. 22:55 CST, and made contact with Operator2.  Operator2 advised that he and his passenger (V2 occupant) were headed up the lake in his bass boat when they suddenly noticed a boat in front of them.  Operator2 turned his steering wheel to the right to avoid hitting the other boat in the rear, but in doing so caused the starboard (right) rear side of his boat to strike the port (left) rear side of the other boat.  Operator2 then pulled around the other side of the boat he hit and turned on his docking lights to check on the other boat.  Once Operator2 and V2 occupant determined there wasn't any injuries, they asked the other boat "where are your lights".  Operator2 and V2 occupant stated that a male passenger on the other boat then moved an American flag to reveal the stern light, which was on.  
       I then spoke to the operator (Operator1) of the other vessel, a pontoon boat with seven passengers.  The first thing the Subjects expressed was how fast the bass boat was going.  The Subjects then stated that they were out just idling along enjoying the stars, when they heard a boat coming up behind them and before they knew it, the boat had hit them.  All occupants of the pontoon boat had similar statements of how they heard the boat coming from behind and being hit with no warning.  Subject1 stated he noticed the boat approaching quickly and thought it would hit them directly in the rear, and he began to holler but the engine from the bass boat was too loud and he didn't think the other boat heard him.  
       I interviewed operator1 and husband, and they both stated that their navigation lights were working and were not obstructed.  They advised me that their lights had quit working shortly after the accident, but showed me where the flag was hanging from the back of their boat.  From what I saw it did not appear that the flag could have obstructed the view of the stern light.  All occupants of the pontoon expressed great concern about the speed of the bass boat.  Written statements were taken from all the occupants of the Subjects vessel.
       I then interviewed Operator2 and  V2 occupant and asked about their speed of travel.  Operator2 advised he was on plane and typically while on plane he runs about 60mph during the daylight and about 40 mph when its dark.  Operator2 and V2 occupant both advised that they did not see any lights until after the collision, but agreed they were on and didn't think they would have had time to react to turn them on if they had been off.  I asked Operator2, when did he realize that there was a boat in front of him.  He and V2 occupant think that their front navigation lights lit up the back of the pontoon and then they realized a boat was in front of them.  Written statements were taken from both Operator2 and V2 occupant. 
       I interviewed both parties again the next day and their statements stayed the same.  The Subjects say their lights were on and unobstructed, but the bass boat was traveling way too fast.  The Subjects did advise they were having electrical issues with their vessel after the accident and now it would not run at all.  Operator2 admitted he was on plane, but did not see any lights until after the accident when he thinks someone moved an American flag to reveal the stern light which was on.  
       It is my opinion that the primary cause of this accident was excessive speed for the light conditions.  The night of this accident, the lake was extremely dark with very little to no moon light.  Both parties agree that the navigation lights on the Subjects boat were on, and I did not see any evidence that the stern light was obstructed.  It is possible that Operator2 and V2 occupant were sitting so low in the bass boat on plane that they could have been looking upward at the back of the pontoon boat, due to such a close proximity.  This could have possibly caused the American flag to block the view of the stern light, but again the speed of Operator2's boat would  be the primary cause of the collision.