Just got back from Bali, where I took a short trip to Gili Trawangan island to do a freediving course. What can I say - 5 days of freediving (originally was 2 days but Mike threw 2 more days in just because I was already there), 1 instructor per 1-2 students, 30+m depths within 50 metres from the shore, with 70+m depths easily accessible by a boat!!!
Very profound course with lots of 20+ metres diving every day. Broke a couple of my pbs there, 31m being the deepest dive. Thinking about getting a tropical wetsuit and go back there for more, my 3mm spearfishing wetsuit was just too bulky. Haven't done a course in Thailand, so I can't compare, although Bali seems to be easier to get to and greater depths for those who are willing to go deeper than 40m. Anyway, another location to do a course or just social freediving. I can definitely recommend it. It's also a "party" island, in case freediving isn't enough fun for you.
http://www.freedivegili.com/