V1 WAS HEADING WESTBOUND ON BISCAYNE CANAL AT SPEED OF APPROXIMATELY 15 MPH.  V1 WAS TURNING LEFT ON THE C-8 CANAL.  V1 OPERATOR CLAIMED THAT HE WAS HAVING PROBLEMS WITH THE STEERING CONTROL OF THE PWC THROUGHOUT THE DAY.  V1 TOOK THE TURN TOO WIDE AND STRUCK A ROCK ON THE SHORELINE CAUSING BOTH OCCUPANTS TO BE EJECTED ONTO A ROCK.  BOTH PERSONS ON BOARD RECEIVED INJURIES FROM STRIKING THE ROCK.  THERE WAS DAMAGE TO THE BOTTOM OF THE PWC FROM STRIKING THE ROCK.  STEERING WAS INSPECTED AND DID NOT SHOW ANY SIGNIFICANT SIGNS OF IMPAIRMENT.
MIAMI                         