A salvage team removed a car from the Audley Weir in the Royal National Park on Monday afternoon following a crash the previous night.
The black Holden Captiva is believed to have left the weir and plunged into the Hacking River after the driver suffered a medical episode shortly after 8pm on Sunday night.
A number of motorists rushed to the aid of the male driver who was the sole occupant of the vehicle.
Witnesses jumped into the water and began assisting the man and were able to get the man out of the car and onto a surfboard before removing him from the water.
Emergency services including Ambulance NSW, Rural Fire Service, Sutherland Shire Police Area Command and Fire & Rescue attended the scene.
Paramedics treated the man for a suspected heart attack before he was transported to St George Hospital in a stable condition.
