Koh Samui underwater heaven is one of Thailand’s best scuba spots. From friendly giant like blacktip sharks to colorful Spanish Dancer Nudi branchs, wide array of marine species can be found in this amazing gem of Thailand Gulf. Sail rock, arguably the most famous diving site in this area, is only 50-min away from Koh Samui by speed boat. If luck is on your side, lovely whale sharks will come and greet you. Yellow fusiliers, barracudas, giant morays, large groupers and many more are among Koh Samui’s scuba highlights.