RedactedNarrative: Before launching, Vessel 1 was rigged by Witness 1.  The soon-to-be Operator and Occupant aboard Vessel 1 then brought Vessel 1 from the launch area to Lakeside Beach; as they were not familiar with the rigging of Vessel 1, they did not check the rigging prior to launching.  After being underway for approximately 15 minutes, the boom on Vessel 1 separated from the mast, striking the Occupant in the head.  Following the incident, the Operator and the Occupant tried making a temporary fix to the boom, however it would not stay in place.  As a result of the issue, it took the Operator and Occupant more than two hours to get Vessel 1 back to the beach.  While attempting their return, they also called Witness 1 on the phone for help and were advised to come in.  Despite switching positions several times while in transit back to the beach, the Occupant was struck several additional times in the head, resulting in a head injury.  Once Vessel 1 returned to the beach, the Occupant's parent noticed the injury and transported to the Victim to the hospital for treatment.