Man drowns at popular South Australian beach

A man has died in a suspected drowning at a popular Adelaide beach.

The man, aged in his 40s, went for a swim off the Glenelg jetty about 7.50am this morning.

Onlookers saw him go underwater, but he did not resurface.

A paddleboarder found his body floating in the water around half an hour later.

Police and paramedics conducted CPR but they were unable to revive the man.

A report is being prepared for the coroner and police have urged anyone who saw the man before he swam off the jetty to call 1800 333 000.