I tell about extreme sport for me. I choose free-diving. Because I think free-diving it is skill of challenge players. It allows us to be a part of nature same creatures in the sea. The players must pratice meditation. It's dangerous no equipment and safety. But will prepare check from a distance for the safety of player. The prepare play free-diving must it passionate and practice. This sport can search from Internet website, socail, guidebook and free-diving club. Moreover we can play in Thailand as Koh Lanta, Koh Ha, Koh Tao and Phuket.