Officer Nicholas Aspromgos responded to reports of a car in the Bay Shore Marina at about 1:00 on Saturday afternoon. He arrived to find a 97-year-old woman inside the partially submerged vehicle.
The officer smashed a window and pulled the woman out of the car.
A by-stander helped lift the woman to the dock. She was taken to the hospital with non-life threatening injuries.
Police are still investigating how she and her car ended up in the water.