Tourist dies off the coast of SA in holiday tragedy

A foreign tourist aboard a chartered boat trip has died after being pulled from the water in South Australia's Eyre Peninsula.

The woman, 41, was dragged back onto the boat after being found floating unconscious off the coast of Tumby Bay.

She was raced to the Tumby Bay Hospital following the boat's return to shore but despite frantic efforts, she could not be saved.

Paramedics awaited the boat's return.

The tourist was one of 19 passengers on board the Adventure Bay fishing charter. It had set off from Port Lincoln Marina at 8am on Thursday for a half day tour.

Visitors aboard the boat had been offered the chance to swim with sea lions.

Just hours into the trip the woman was spotted in trouble after leaving the boat to go snorkelling.

Part of the trip was the chance to swim with sea lions.

It is unclear if the woman drowned or suffered from a medical episode but police say her death isn't being treated as suspicious.

Those on board carried out CPR during the one hour journey back to shore.

When contacted by 7 News, the charter operator would only comment that the incident was distressing for both passengers and staff.

The woman was rushed to Tumby Bay Hospital but could not be saved.

Adventure Bay Charters also runs shark diving and cruises and has won multiple awards.

Police will now prepare a report for the coroner.