RedactedNarrative: The operator of V1 was traveling upstream with his drain plug open trying to remove the water out of the boat.  He looked back & realized the water was not going out so he reached back to unplug the drain. While reaching back with his left hand, he jerked the steering wheel & hit a tree with the bow of the boat.  The tree was in the water due to the flooding. The arm of the seat he was sitting in hit him on the right side lower back rib area. He was transported to the hospital & determined that he had bruising in the lower back rib area on the right side.  The operator was not wearing a life jacket.