This is the dramatic moment a group of tourists clung to a pontoon after being caught in a rough sea in Thailand.

Holidaymakers and their tour guide were stranded on the floating platform as heavy rain and strong waves hit the Coral Islands in Phuket.

Footage captured by tourist Agnes shows the group huddled together, waiting for the ocean to calm before crossing the pontoon back to shore.

They were seen without life vests and only wearing flip-flops, raising the risk of slipping and falling into the sea during the downpour on July 20.

Agnes said: 'It was sunny at first during our trip to Racha Yai and Coral Island, but after 3 p.m. it turned cloudy. As I walked on the dock, it began to rain, but I wasn't too worried since others were ahead of me.

'Then the rain got heavier. I sat in the middle of the dock, hoping the waves wouldn't knock me over. A guide helped me join the others, including a girl who was shivering. The boat struggled to reach us due to the rough sea, but the guide stayed calm and helpful.'

Thailand's Meteorological Department issued weather warnings when Wipha was recorded as a strong tropical storm over the northern South China Sea at 10 pm on July 19.

With maximum sustained winds of 93 km/h, the storm moved towards the Gulf of Tonkin and northern Vietnam, where it is expected to weaken into a tropical depression between July 21 and 22.