Koh Tao island is the island to go scuba diving. Whether to free dive, get your cetification, advanced, or dive master program this island has a plethora of options and dive shops. I took my certification by Big Blue. I was impressed with the professionalism with this organization. Accomadations were included when I enrolled in my classes. There is a bar, stunnning ocean front views, walks from restuarants and any you could ever ask for.