America News Agency

The 21-year-old Chinese national, who was swimming with a rubber ring, was swimming at Shirahama Ohama beach with a friend at around 7:30 p.m. Monday, the Coast Guard said Thursday.

Authorities launched a search and rescue operation after her friend raised the alarm at the beach in central Shizuoka Prefecture that evening.

The woman, whose name was not released, told rescuers that she had been swept out to sea and was unable to return to shore because she was swimming with a rubber ring.

The official said the woman was finally spotted swimming off the southern tip of Chiba's Boso peninsula by a cargo ship at 7:48 a.m. on Wednesday.

Two crew members of a nearby smaller tanker radioed in and jumped overboard to rescue her.

"There are 80 km in a straight line between the coast and the rescue point ... but it is assumed she drifted an even longer distance," the official said.

After the woman was rescued, she was taken to hospital, but hospitalization was not required as she was mentally stable and the dehydration was not life-threatening.