A man has drowned while scuba diving at American River on Kangaroo Island.
Police said the man, in his 60s, was found unconscious in the water on Sunday afternoon.
Emergency services were called to the local boat ramp just before 5pm.
"Desperate efforts to revive the man were unsuccessful," police said.
Police said the man's death is not considered suspicious and a report is being prepared for the coroner.
Last month, lifesaving authorities expressed concern about the number of drownings in SA waters this summer after the death of a man at Grange, who had gone into the water to rescue his daughter.
Emergency services were also called to two fatal crashes on South Australia's regional roads over the weekend.
A 37-year-old Victorian man died when his car crashed into a tree at Frances near Naracoorte in the state's south-east.
Emergency services were called to Frances Road just after 11:30am on Sunday.
The man is the sixth person killed on the state's roads this year.
The previous night, a driver crashed into a stobie pole on Proper Bay Road at Tulka near Port Lincoln.
The 46-year-old local man died at the scene and a passenger suffered critical injuries.
The 53-year-old Whyalla Stuart woman was taken to the Royal Adelaide Hospital.
