From 1933 to 1947 Koh Tao was used to jail political prisoners of the Bowaredech Uprising. Many were transferred from Koh Tarutao to Koh Tao because of its isolated location in the middle of the Gulf of Thailand.
The first real settlers arrived in 1947 from Koh Samui and Koh Phanghan. Before then, only passing fishermen and the occasional coconut harvester had come ashore.
Over the past 20 years, Koh Tao's reputation has grown. Word has spread of its abundant marine life and impressive coral reefs. It has become one of the major dive sites in South East Asia.
From Bangkok, you can either take a plane to Koh Samui and then a boat via Koh Phanghan to Koh Tao. Or, the cheaper alternative is to take a bus/boat combination from Bangkok to Chumphon on the mainland and then on to Koh Tao.