Phuket, the biggest island in Thailand, is situated during the southern part of the region, throughout the Andaman Sea. The island is characterized by its mountainous terrain, which has a mountain selection extending from your north into the south along its western side. Phuket has some good dive web pages. https://howtogeeks.co.uk/exploring-the-beauty-of-phuket-a-jet-ski-tour-adventure/