RedactedNarrative: At around 1250 hours in front of Jonathan Creek boat ramp on KY Lake, OPERATOR 1, was attempting to start a pontoon boat that he had purchased the day prior. 3 male juveniles were in the water swimming near the rear of pontoon. According to operator and witnesses, the outboard started and was in neutral but the outboard went into gear and the propeller struck SWIMMER 1, causing multiple deep lacerations down the length of his right side. SWIMMER 1 was airlifted to Nashville. I arrived on scene while victim was being given medical aid.  No persons were wearing pfds and no alcohol was found or suspected.   