There are several different places to dive around Koh Tachai and the most popular is Koh Tachai Plateau about 1km off the south eastern side of the island. There is a mooring buoy marking the site and it is usually necessary to use the line to prevent being swept away from the dive site by the current. The plateau is a scattering of rocks piled around each other that start at around 13m and drop down to past 35m. The rocks are covered with corals, sea fans, crinoids and anemones.