RedactedNarrative: Operator was operating pontoon on the WI River traveling north towards Blackhawk Island by high rock on the east shoreline. Just after passing he rock he and all the individuals on board had heard a scream from behind the boat. Prior to passing high rock they observed three individuals standing on high rock and when they heard the scream did not know if somebody had fell or got injured. Operator turned to look and had to lean over towards the starboard side of the boat to see out from under the pontoon. Operator felt this caused him to steer the boat starboard striking the rock wall near high rock. Operator did not see the rock wall approaching due to looking towards the rear of the boat. Upon striking the rocks subject was thrown into the front deck rail gate edge causing a cut to her head.