Update: for accurate information on the accident see the discussion on Scubaboard [9 December 2010]
Update: Peter McCarthy was with one other instructor. There were no tourists, just the two of them in the cave [source: pers. com. to webmaster 2 December 2010]
Nakhon Si Thammarat: A British diving instructor is missing after he led nine foreign tourists on a dive at the scenic Song Hong Lake in Thung Yai district, police say.
A rescue team was called in to the lake where the tourist divers were searching for their instructor, Peter McCarthy, 47.
Heavy rainfall yesterday evening forced the rescuers to call off the search. It will resume today.
Mr McCarthy took the group on a diving expedition at the lake yesterday morning. He disappeared later on in the afternoon.
Song Hong Lake is known for its depth which can extend down to hundreds of metres in some spots. Its bottom is naturally shaped like two rooms (song hong) with labyrith-like caves inside.
Bangkok Post
30 November 2010
This Bangkok Post report isn't in their online edition.
Some updated information is available on the ThaiVisa forum http://www.thaivisa.com/forum/topic/422687-british-diving-instructor-feared-drowned-in-thailand-after-failing-to-return-to-surface-while-with-tourist-group/
There is an online report at http://phuketwan.com/tourism/instructor-vanishes-gulf-danger-dive-13330/, but this report is garbled and claims it was a sea dive near Ko Tao.
The Phuketwan story has been lifted by the Daily Mail http://www.dailymail.co.uk/news/article-1335108/British-diving-instructor-feared-drowned-Thailand-failing-return-surface-tourist-group.html, and also claims it was a sea dive near Ko Tao. In turn the Daily Mail report has been lifted by a other news sites and blogs.