I WAS DRIVING AROUND OUR LOCAL LAKE DOING 25 MPH. I HAD JUST COME AROUND A CURVE AND WAS HEADED FOR ANOTHER CURVE PRETTY QUICKLY. ALL OF THE SUDDEN THE CAR STARTED SPEEDING UP ON ITS OWN. I TOOK MY FOOT OFF THE GAS PEDAL AND I HIT THE BRAKES TO TRY TO SLOW DOWN AND NOTHING HAPPENED. THE CAR CONTINUED TO SPEED UP ON ITS OWN. MY SPEED GOT UP TO ABOUT 40 MPH WHEN I CAME UP ON A CURVE. I SLAMMED ON THE BRAKES AGAIN AND TRIED TO TURN THE WHEEL BUT I HAD NO CONTROL OVER THE CAR AT THIS POINT. IT CONTINUED TO ACCELERATE AND I MISSED THE CORNER AND LANDED IN A POND ON THE OTHER SIDE OF THE LAKE IN ABOUT 3 1/2 FEET OF WATER. MY CAR WAS THEN SUBMERGED UP THE TOP OF THE TRUNK IN WATER.