The body of a Chinese tourist missing since going swimming at Karon beach on Thursday night was found on rocks near Freedom beach in Phuket on Monday.
A fisherman discovered the body and informed police about 9.30am.
Rescue workers said Qin Yuan's body was lying on the rocks, and was taken to a hospital for post-mortem examination.
Qin, 27, was last seen about 7.30pm on Thursday.
Karon's mayor said a Chinese couple had rented a surfboard on Thursday evening and returned it about 6.30pm.
The couple again went swimming at Karon beach about 7.30pm. By then it was dark and all the lifeguards had left the beach.
Rescuers began a search after being alerted that the woman was looking for her missing husband.
The municipality had earlier put up no-swimming signs in four languages - Chinese, English, Russian and Thai - and placed red flags along high-risk parts of the beach. Many people ignored the warnings.
Nine people, five of them foreigners, have drowned this year in Phuket.