RedactedNarrative: Operator and his two friends were taking turns tubing and swimming.  Operator had been drinking.  He didn't have a lot of experience with this type of vessel and had borrowed it from a friend for the day.  He came around a turn at a high throttle and was unable to bring the wheel back to avoid the collision with the injured being towed.  He admitted that he didn't think to throttle down or stop the boat.  The passenger told injured to jump off the tube and at that point the vessel ran over the injured and he was struck by the propeller causing injury.  Responding officer decided that he detected a slight odor of intoxicants on operator's breath but determined he was not impaired at time of accident.  Injured was in recovery and did not drink.  There were 10 full and 10 empty bottles of beer on board.  Investigator issued a written warning for operating a boat negligently so as to endanger others.  Operator operated at a speed that was beyond his ability to control and that he was responsible for the accident.