Even the most biased Thai Bay will admit that, for pure diving reasons, the best place to dive in Thailand was found on the west coast of the country, in the Andaman Sea. Yes, maybe there are some great experiences that must be experienced when diving from Koh Tao, and even Koh Chang, but the depth of water, clarity, and marine life means that diving in the Similan Islands, or other Andaman Sea Dive areas in general and consistently better and consistent.
On the west coast of Thailand, there are two main areas where the Liveaboard submarine boat sailed around a full enthusiastic diver to jump and see something special. You can choose Phuket Dive Centre for PADI Scuba Diving, Thailand Via Sirolodive if you want to learn scuba diving.
Eight of the main islands and dozens of islands are home to more than twenty fantastic dive sites, with tilting coral reefs or granite rock formations. To the northeast or the Similan Islands, and the Northwest of Tab Lamu, are Richelieu Rock, Koh Bon, and Koh Tachai, the three of which make Thailand's best dive spots for those who want to dive in clear waters and see species of large pelagic fish. The third area is Southeast Phuket and South Koh Lanta.
Similan Islands are basically uninhabited. There are several Park Rangers who live there to protect the national park. Scuba Diving in Similan Islands is quite extreme even for the brave scuba divers, the depth and current to meet every taste. However, there are also many opportunities for new divers certified to spend an hour underwater here.
Even those who have never dived before can try scuba diving in the Similan Islands. Reefs are home to tens of thousands of colorful and interesting species, and the condition of the sea and weather during the diving season is second to none. Cruises Liveaboard, or Scuba Diving Safaris when some call them, almost always give guests some opportunities to roam to the beach and do some trekking or relaxing hours.