A man has died after his car drifted out to sea.

Police say the four-wheel-drive got stuck in sand about 8:30pm ACDT on Sunday at the Murray mouth at Goolwa, south of Adelaide.

Witnesses said the vehicle was being driven along the beach earlier.

The current dragged the submerged four-wheel-drive into deeper water.

South Australian police divers recovered the victim's body and the car in the early hours of Monday morning.