In reply to jussy: Hi mate i was in Thailand a few weeks ago. We went on the boat from Phuket town to Koh Phi Phi it was about 600b we stayed for 5 days on the island. The climbing on the island was DWS and Sport inc multipitch. There are various climbing shops on the island but i recommend Deaf Gecko on Tonsai beach they are right next to the main cliff, are very friendly and climbers themselves. It was around 1200b for the dws and about 1000b (20 pound) for gear hire. I know you said boulder in the OP but thought i would give you an alternative.