In December 2005 three technical divers, Bruce Konefe, Cedric Verdier and Mike Gadd, were on a cave diving expedition to Krabi. The first part of the trip was in a National Park based on floating bamboo huts (a photo of their floating camp looks like Tone Teuy in Khao Sok National Park in Surat Thani) and all diving equipment had to be brought in. Exploring the area by long-tailed boat, passing nothing but limestone walls and cliffs, a cave entrance at water level was found after an hour. Two reels of line were laid in this beautiful cave at a maximum depth of 28m.
The second part of the trip was to push Thamn Sra Keao near Ban Nai Sai on the H4034 a few kilometres north-west of Krabi town. This vauclusian spring had been dived by Matt London and others in 1999 to a depth of 120m. The first dive on Christmas Day was to -80m staging tanks at 6m, 21m, 40m and 80m. The next day the line was extended from the old end at –117m to –127m. Finally, on the 27th December, the cave was pushed from –127m to –150m where there was a large chamber. The water was described as being gin clear below 90m and 26°C. The cave has almost no speleothems, but does have a lot of shrimps. There are a few side passages in the cave at a depth of 60m to 80m, but it is difficult to see the walls in places.
The divers hope to return to continue the exploration of Sra Kaeo and cave diving courses are already being run in the cave found in the National Park.
References:
http://www.rebreatherworld.com/rebreather-cave-diving/2608-new-cave-deep...
http://drmike.smugmug.com/gallery/1098645