I think Pattaya is the place...but May/June?? Most windsurfing in SE Asia is based around the NE Monsoon, which is roughy around the Northern winter months (when it's summer in Australia - did you know that?). You might catch the "opposite" monsoon season, the SW, but it's not usually as good and in some places it may be crap.
Check SE Asia's best windsurfing forum -
www.bluefinz.com -someone will be able to help!
