RedactedNarrative: Boat had just been launched from boat launch and was being driven south from the landing. The boat was at cruising speed on plane. According to occupant, operator was driving and had turned back to look at Occupant. Occupant believed that Operator had let go of the steering wheel or did not have a firm grip. The boat suddenly snapped into a turn. Occupant believed the boat turned to the right, and he was thrown over the port side, and operator was then thrown over the starboard side getting struck by the prop. The third person remained in the boat. The boat was then going in circles. The third person was able to shut off the boat and others came to help.