The operator of Vessel 1 was towing his son, who was wakeboarding.  The son (the injured party) attempted to perform a trick, but the edge of the wakeboard caught the water and caused him to fall face-first into the water.  He did not initially appear to be injured, but after consulting a doctor, the operator of Vessel 1 noticed that his son was exhibiting signs of possible concussion.  The injured person was transported to a hospital, where a CAT scan revealed no major injuries but doctors suspected a mild concussion.
Alton                         