I have never been diving in Thailand or Burma.  But after watching this video it has become high on my list.  Even if you are not a diver, you can watch snorkelers swim with a whale shark. I hope you enjoy the video.  It is really well done.

http://www.dailymotion.com/relevance/search/scuba+diving/video/x13dsb_scuba-diving-in-thailand-and-burma_animals