Terrified tourists were battered by storms while taking a boat from a Thai island.

Footage shows the Aussie holidaymakers clinging to their seats as strong winds slammed the wooden vessel off the coast of Koh Samui in Surat Thani province on June 7.

The ferry was rocked by powerful waves crashing against the sides, while torrential rain pounded the roof overhead.

At first, the swaying was manageable, but as the downpour intensified, everyone stayed huddled under the covered section wearing life jackets.

Australian Caitlin Lee said: ‘We took a longboat during the rainy season in Koh Samui. We got caught in a storm.'

Thailand and neighbouring countries in Southeast Asia are at the start of their annual monsoon rainy season which sees soaring temperatures followed by powerful rain storms. The rudimentary infrastructure often struggles with the deluge, leading to widespread flash floods.