There are many Island in Thailand. Ko Phi Don, Ko Pha Ngan and Ko Rang Ko Chang these are best Island in this place. My family visited these islands and spent good time. They have enjoyed their Diving at Chaloklum Diving. That experience was great. Tropical Dive Club, Haad Yao Divers also best places for divers. I visit these divers in my various tours. I am sure if you will visit there so you will enjoy there.