A TSUNAMI-like torrent of rain is likely to lash Phuket for days yet as a meteorological officer described the continuing Phuket downpour today as ''the worst in living memory.''

More than 300mm is tipped to be dumped on Phuket in the next 24 hours as the Royal Thai Navy rescued tourists from the outlying Similan and Surin islands and Phuket emergency workers prepared for flooding and landslips.

''The really worrying thing is that the monsoon depression over Phuket shows no sign of moving,'' the meteorological duty officer told Phuketwan today. ''I have been talking to people who are in their 70s and have lived on Phuket all their lives, and they have never seen any time when the clouds have opened like this.''

So far there have been no reports of dangerour flooding or of landslips, but Phuketwan reporters went to the scene of a building collapse in the Phuket City suburb of Sam Kong last night where a tin construction collapsed onto the roadway, hitting motorcycles but no people.

Rescue missions by the Royal Thai Navy returned to shore last night carrying grateful tourists who had been stranded since Saturday. The frigate Bangpakong picked up 37 Thais and 47 expats, including nine children, from Koh See (island No. 4) in the Similans and docked at Tablamu, north of Phuket, about 8pm.

A second vessel docked further north of Phuket at Kuraburi at 11pm with tourists who had been rescued from the more isolated island of Surin.

Estimates of the damage being done to tourism on Phuket and throughout the south of Thailand are difficult to gauge at this stage, but concerns are mounting for hundreds of tourists stranded on Samui in the Gulf of Thailand, with the airport closed and ferries no longer operating.

Phuket, with better infrastructure, has so far kept its airport open, although the cost to the tourism industry of cancellations and for tour companies that cannot operate is taking a huge chunk from what had been a successful high season.

Suchart Hirankanokkul, President of the Thai Hotels Southern Chapter, told Phuketwan today: ''Tourists are locked down in their hotels.

''We will be trying to assist everyone in need by providing accommodation free of charge for those people who have had to be rescued, through no fault of their own.

''At times like these, Phuket has to show it has a big heart and help as much as we can.''