Like Ao Phang-nga, Mu Ko Similan are also preserved as a national marine park, extending over an area of 32,000 acres. Set in the Andaman Sea about a 3-hour boat ride from the mainland, the nine islands of the archipelago are quite distinct from those of Phang-nga. The islands are of granite, not limestone which makes them a rare beauty. The formations are also uniquely different. Together with hiking trails and other onshore attractions, however, Similan’s reputation is its 30 excellent and dissimilar diving sites. Coral walls, huge sea fans and barrel sponges, rock reefs, swim-throughs and other underwater features offer a wide variety of opportunities for experiencing, while plenty of shallows afford excellent conditions for snorkelling.
Ko Similan is the largest island with a large beautifully curved bay named Qo Kuerk. The beach here is white like powder. Snorkeling is possible from here. To the right is found the towering 'Sailing Rock', a symbol of Ko Similan which can be climbed in order to take in a panoramic view of the bay.
With sufficient supply of fresh water, Ko Miang is the second largest island where the office and guesthouses of the Similand Marine National Park is located. The island is famous for its beautiful beaches and colourful coral reefs.
Ko Payu or Ko Jed (Seven) has a very stunning snorkeling and scuba-diving site on the eastern shore. Many divers prefer this site to any other because there are both hard and soft corals, sea fans, and many species of schooling fish. A minor site is found to the west, and another to the north has rocks covered with sea fans, The island has no beach.
Ko Haa (five), to the west of the island is a large underwater rock full of soft corals. Nearby, garden Eels can be seen stretching their necks from holes in the sandy floor.
Ba Ngu or Hua Ka Lok Island
Ko Hua Ka Lok or Skull Island is the seventh island in the Similan group. A rocky island of peculiar shape, it looks like a skull when viewed from one certain point. Ko Hua Ka Lok is renowned for its breathtaking underwater beauty on a many-tiered seabed.
Hu Yong Island
Ko Hu Yong is well-known for its longest strethch of white sandy beach where sea turtles lay their eggs.
Ko Bon is located between the Similan Islands and Ko Tachai. There is no beach and the underwater scenery here is not as beautiful as elsewhere, but scuba divers may often find Manta Rays.
Ko Tachai is located at the northernmost tip of the park. There is a beautiful white beach on the island but no accommodation. The water is suitable for scuba diving, and Whale Shark is often found here.
Diving can be done around the island. The north is Deep Six rock. The west is rocky line switching with small corals. The large massive corals usually are in the deep area. The east is the most suitable spot for diving. The coral reef steep slopes down. At the depth of about 25-35 meters, there are large massive corals with very beautiful soft corals and sea fans. Along the shallow edge of 5-10 meters deep, there are also massive corals and soft corals. A lot of fishes can be found in the area. It is one of the most beautiful spots of the park.
Here is the diving spot that appropriate for the review dive. The sand floor is about 5-10 meters deep. The current is not so strong. There are massive corals scattering in small groups with sea fans and soft corals living in. At the end of the west is Hin Muan Diaw, the large rock with plenty of soft corals and sea fans. The surrounding sand floor is eel garden found a lot of garden eels living in. Beyond that area is coral jungle where a Harlequin Ghost pipefish is found.
It is the underwater rock at the north of Ko Kao (Ba-Ngu) with the depth of 15-30 meters. Below are complex rocks similar to Fantasy Reef. There are a lot of fishes and nudibranchs.
Hin Ka Lok (Ko Jed, Hin Pusa)
It is a small exposed rock surrounded by seawater of 20-50 meters deep. Sometimes there is strong current, it should be very careful. There is a Model Window, a hole that can push your face forward for taking a photo. In the area often found sea turtles and Mantis shrimps. There is also a report of a frogfish in the area.
Almost all of coral reefs in Similan area are deepwater coral reefs without certain edges. The coastal side is sand floor before rapidly sloping into the blue sea. Coral reefs are in-groups, not scattering around like other general coral reefs. In order to make your snorkeling more enjoyable, we would like to suggest these selected areas.
It can be reached by walking from the park's lodgings (the same trail as Hairy Leg Mountain crab observation). It is the beach of clear water with coral reefs spreading in-groups. Beautiful fishes can be found like Red Saddleback anemonefishes, butterflyfishes, and angelfishes. Haad Lek is the suitable place for practicing diving because there is no boat expense and short time is required (walking only 20 minutes). It is safe if you do not swim far away from the shore. Haad Lek is also an exciting snorkeling night diving place (for trained person only).
It is located in the northwest of Ko Similan or Ko Paed. It is a big bay shaped as a horseshoe with beautiful white beach, and Hin Bai (Sailing Rock) or Donald Duck Rock, the symbol of Similan.
Coral reef in Ao Keuak is in shallow water. You can swim from the shore. Mostly are branching corals. In the past, they are very elegant, but now are in deteriorated condition. However, it is still beautiful enough for somebody to be impressed in underwater world. Especially, for the night-dive SCUBA diving, it is a suitable place with a chance to see many crustaceans such as Spiny lobsters and Slipper lobsters.
Coral reef at the east of Ko Hok (Payu) is one of the most beautiful shallow-water diving spot. The inside coastal shore is sand floor with some Staghorn coral in-groups, the outside coral reef edge is about 5-8 meters deep with large massive corals. Many corals have a lot of soft corals and sea fans. And it is the only spot in Thai Sea that this soft coral species is found in the shallow water that can be seen from the surface. (Usually it is found at the depth of more than 10 meters.) Our team has ever found a big shark coming in near the shore.
Comparing to Ao Keuak, Ko Hok has more beautiful coral reef. However, there is no sandy beach for coming up (or have some but difficult to come up), only buoy can be used for diving. Therefore, there are few visitors here.
During the open season (from mid November to mid May) both speed boat and slow boat ferry are available daily at Lab Lamu pier in Phang Nga, on highway no. 4. Groups can charter the whole boat. The distance is 70 km. Phuket also have boat services to the Similan islands.
Limited bungalows are available on Koh Si (no 4 island or Koh Mieng) and Koh Paed (no 8 island or Koh Similan). Camp grounds with tents, and restaurants are also available on these two islands.
Park's mainland visitor center is 5 km before reaching the Tab Lamu pier. Phone number is 076-595 054. On Koh Mieng or Koh Si (island no. 4) there is a headquarters for the islands.