Thai and foreign divers will launch a search of the missing Russian girl by scouring the sea at five diving spots around Chaloke Ban Kao bay Today.
The underwater search followed a meeting on Monday between Koh Tao police headed by Pol Lt-Col Chokechai Sutthimek, chief inspector of Koh Tao police, and representatives of diving companies.
Police have shifted their attention to underwater search after it was learned that the Russian, 23-year old Ms Valentina Novozhynova, was a free diver and that she might have gone missing while diving.
Examination of CCTV system on the popular island found out that the Russian woman went into a convenience store near her hostel, Koh Tao Hostel at about 8.45 am on February 15. A party was held at an entertainment venue on the night of February 15 and police were investigating to find out whether the Russian attended the party or not.
A French free diving instructor, meanwhile, said that she usually teaches her students to dive at depth between 10-20 metres.
Police said that the Russian had communicated with a friend online that she would try to break her own free diving record of 22.3 metres. She was seen on CCTV leaving for a diving session on February 16.