RedactedNarrative: SUBJECT WAS OPERATING VESSEL (JET SKI), CRUISING ALONG THE RIVER CHANNEL.  SUBJECT CHOSE TO TAKE SIDE TRIBUTARY, INSTEAD OF MAIN CHANNEL, TO AVOID SLOW SPEED AREA.  SUBJECT WAS UNAWARE, THE WATER LEVEL HAD REACHED A LOW POINT AND A SANDBAR NOW EXISTED IN THE TRIBUTARY.  SUBJECT IMPACTED SANDBAR AND WAS THROWN INTO THE JET SKI'S EXTERNAL STRUCTURE.  IMPACT TO SUBJECTS BODY CAUSED BROKEN LEG BONE (TIBIA), CONTUSIONS, AND LACERATIONS.  SUBJECT'S JET SKI WAS NOT DAMAGED.;