A 50-year-old father and his two sons have been rescued after they were found adrift off the Thai island of Koh Samui, a local official told AFP on Saturday.

They had spent more than 16 hours floating at sea after their jet ski capsized, local government official Amorn Chomchoey said.

"We found the exhausted after swallowing a lot of seawater," he told the news agency, adding "they were pale, especially the boys".

The family were checked in hospital after being rescued and were discharged shortly afterwards, Chomchoey told AFP.