Ko Lanta lied on the west coast of Andaman Sea in between Krabi and Phi Phi Island . Large Size Island with 6 km wide and over 30 kms long, 9 beaches lie from north to south along the sunset coast. Stunning scenery, fantastic white sandy beaches, coastlines have more than 70 small islands and plenty with forest, coral reefs and under water life.
Exposed to the Tsunami hit southern Thailand , Koh Lanta got very little physical affected. She has been quietly recovering with most hotels operating normally.
Koh Lanta was very fortunate in that no damage occurred to the natural scenic beauty. All the beaches remain as beautiful as ever. All dive sites did not suffer in the disaster, rather the water is cleaner and clearer than ever
Dive Site Ko Lanta 
Andaman sea was named as the best area for diving in southern part of Thailand. But one of the best part is southern of Andaman sea which the greatest site “Hin Daeng & Hin Muang” - world top ten rated by international dive magazine located. Any divers who need to spend a quality time of diving in Thailand should base themselves in Koh Lanta. Where easy to access to many popular dive site as Koh Ha - underwater carvern dive and all others as Shark Point, King Cruiser Wreck, Anemone Reef, Hin Bida and Koh Bida.
Hin Daeng (Red rock)
Only reason that diving activity of “Koh Lanta”has become to the world class was “Hin Daeng - Hin Muang” could offer everything as a diving addicted need, settle from dramatic walls, big action of Barracudas crowd, Manta, Whale Shark and the lush tropical underwater gardens.
Manta, Whale Shark and the lush tropical underwater gardens.“Hin Daeng” , about 3 meters left above the surface look like a small ordinary limestone which can be found from every where, but secret was slept under the surface “Hin Daeng” is the Huge rock which the southern side descend straight down to hit the sea ground at 60 meters depth, The most deep vertical drops underwater cliff of Thailand's seas. The cliff is dotted with lighten growths of soft and hard colorful corals and sea fans, all of them come with the same theme of red color “Hin Daeng” in Thai was equal to “Red rock”.
Hin Muang (Purple Rock)
“Hin Muang”, a few hundred meters away from “Hin Daeng”, the submerge rock under the surface, was inconceivable area, numerous of marine life have found between the clunk of huge rock
The name itself “Hin Muang”(purple rock) come from the thick purple growths of soft corals those were found everywhere on the rock. Approximately 200 meters length, almost 20 meters width, and is shaped like a loaf of meat, stand on vertical sides, rounded shape on top. The walls have decorated with large red, orange sea fans, lots of glass fish, or silver sides, marine’s school around the fans surround with plenty of various sea creatures. the shallower sections is the location of the pinnacle carpets of lively sea anemones.
Whale sharks, Manta ray are usually found around these pinnacles rock. This site sometime quite strong current. Experienced divers were recommend.
Ko Ha – Cave diving 
“Ko Ha”, settle from 5 small islands into a group, apart to the west from “Ko Lanta” about one and a half hours this group of islands separated by sections start from 3 - 50 meters depth, Here is characteristically clear water and excellent visibility sometime over 25 meters.
Highlight of diving here is cave diving with a series of underwater caves, the largest cavern of the islands is lies on “Ko Ha Yai”. Cave at “Ko Ha Yai” are safe to enter, even without light, as the large entrances and there is only one way in and one way out .
The best part of entering these caves is that you can ascend to the surface inside heart of island. Scenic of stalactites hanged from the top of ceiling over 30 meters height. Light filtering through the water from the entrance is the touch of the miracle.
This site were recommend to all level divers, and provide you the opportunity to see various fantastic underwater creatures such as Manta Rays or even the giant of the fishes - the Whale Shark also the Little star as Leopard Shark and Giant Turtle.
Ko Bida Nok / Ko Bida Nai
Two small limestone islands; “Koh Bida Nok” and “Koh Bida Nai”, away to the west from “ Koh Lanta” between the route to Phi Phi Island. This site will provide you an excellent and variety taste of diving.
Suitable for all level divers. Start from 8-28m depth. Colourful soft corals mixed with hard colorful coral reefs residential of coral fishes as Muray eel, Scorpionfish, Leopard sharks are also the star here which usually seen on site. At the shallower section will found the sea anemone garden which is the house of little famous star as “Nemo”
Hin Bida
This site has been called "Phi Phi Shark Point" Leopard sharks are the star here. “Hin Bida” located away from “Ko Bida Nok-Ko Bida Nai” a few kilometers. Shape itself as the breaks rock submerge under the surface. When low tide and drops down to hit the sea ground at 18-22m depth, surrounded by boulders, Stag horn corals. Large sting rays are also encountered here. The soft corals at the Southern end of the site are particularly beautiful.
King Cruiser Wreck - Dive site.
On the 4th of May 1997, the 85 meter passenger ferry "King Cruiser" on a routine run to the Phi Phi islands made history by straying several kilometers off course and hitting the Anemone Reef.
With a huge hole ripped through her belly the ship went down in less than an hour and provided the Phuket Diving community, at long last, with her own artificial reef. At 25 meters you'll find the engine room and car desk. Moving up to 18 meters you'll find the passenger section which has the heads, bar and lots of tables and chairs. Even though the ceiling is pretty low it is relatively safe to penetrate as the doors are broken off.
At 15 meters you'll find the captain's cabin and wheel house. The reef is teeming with life and its proximity to Shark Point and Anemone Reef has undoubtedly had a lot to do with it's rapid population growth. The Wreck is an extremely popular dive and considered one of the best in location. 
Article Source : http://www.lantainfo.com/
