It's common knowledge in the diving and snorkelling industry that trippers to the Similans exceed the maximum number of 250 a day.
Captain Thammawat Malaisukkarin, of the Naval Civil Affairs Directorate, has confirmed that 455 passengers and crew were rescued by the patrol ship Pattani from the Similans island of Koh Tachai in a wild storm on April 17.
Although numbers of tourists to the Phuket region continue to increase, the income from the Similans has only risen from 19.7 million baht in 2009 to 20.7 million baht in 2012.
The limit of 250 visitors a day to the Similans is imposed to protect Thailand's environmental marine gem from mass tourism.
Yet the natural reefs and beaches are now alleged to have been turned into a fiddle where rangers and operators pocket the profit from extra boats.
The claims came into focus again in 2012 - and the mass rescue last month proves that more visitors are going to the Similans, and that their park fees (500 baht for expat adults, 300 baht for children, 100 baht for Thais) are not entering government coffers.
Corruption claims were anticipated to be a feature of a summit of Natural Resources and Environment chiefs from key southern provinces at the Metropole Hotel in Phuket City today.
The media was excluded from the meeting - Thailand is slipping back in terms of press freedoms, an international report found this week.
But it's understood that a claim would be raised that rangers were charging 20 baht for admission to ''free'' public toilets in one popular national park and pocketing the cash.
The toilet fiddle would be small change compared to the profits to be made by a Similans scam. Investigators would not have to go far to check it out - they could do what the Navy did and count the people in the park at any one time.
Time is running out, though, for that kind of action. The Similans park is due to shut down on May 15 for its annual environmental respite until November.
There are other claims, though, that boats visit the Similans illegally out of season, with the blessing of rangers.