RedactedNarrative: UNIT 1 WAS TRAVELING WEST ON THE WACCAMAW RIVER.  UNIT 2 WAS STOPPED NEAR THE MIDDLE OF THE CHANNEL ASSISTING WITH PASSENGERS.  UNIT 1 ENTERED INTO A SHARP CURVE WHILE ON PLANE.  UNIT 1 COLLIDED WITH UNIT 2 WHILE UNIT 2 WAS ADRIFT.  BOTH UNITS HAD A SECONDARY COLLISION WITH A DOCK.  SEVERAL PASSENGERS FROM BOTH UNITS WERE TRANSPORTED TO THE HOSPITAL.