Koh Bon

Koh Bon is of great importance to the largest living ray, the Giant Manta Ray

Koh Bon is located between the famous Similan Islands and Koh Tachai. It is known locally as the middle island. Koh Bon differs dramatically from the Similan Islands in it’s topography. Koh Bon has a different look and feel to it.

It is also of great importance to the largest ray that migrates through Thai waters.

Koh Bon in the SImilan National Park

Welcome to Koh Bon

Koh Bon is an unique island compared with the Similan and Surin Islands. Both the Similans and Surin are comprised of huge granite boulders. Koh Bon is formed by sedimented limestone. Referred to as the middle island by the Thais, Koh Bon sits alone 23km northeast of the Similan Islands. Koh Bon was added to the Similan Islands Marine National Park  in 1998.

Like the Similans, Koh Bon is surrounded by the clear, turquoise waters of the Andaman Sea. However the limestone rock gives the island a very different feel. In the bay to the southwest side of Koh Bon it is clear to see the different layers of limestone laid down over thousands of years. The rock is dark and imposing. The dense rainforest of the Similans is replaced by scrub grass and wind swept trees that cling to the rocky top of Koh Bon. Although it is not possible to go ashore at Koh Bon, there is still plenty of wildlife to spot from the boat. Sea eagles soar overhead and herons skim over the top of the water. The dramatic change in scenery at Koh Bon is also apparent when you go snorkeling. The stunning limestone continues down to the depths underwater. The tropical fish life is the same as the Similans. What makes Koh Bon so special though is at certain times of the year it is possible to spot the graceful Giant manta ray (Manta Birostris).

Koh Bon Highlights

Being the focus of a Manta ray, sometimes up to 5m in width is an exhilarating experience and will remain a treasured memory from your snorkeling liveaboard

Koh Bon is an extremely important location on the migratory route of the world’s most endearing species of megafauna, the Giant manta ray. Typically around the new year the number of manta ray sightings increases at Koh Bon. To date, it is still unclear why the manta rays aggregate at Koh Bon. However this is not on your mind when you are snorkeling and encounter one of these truly impressive creatures.

Manta rays are curious animals and are frequently spotted near the surface. You don’t have to scuba dive to see them, you are as likely to be approached snorkeling. Being the focus of a ray, sometimes up to 5m in width is an exhilarating experience and will remain a treasured memory from your snorkeling liveaboard with Andaman Snorkel Discovery. Koh Bon’s location and underwater topography shape the underwater landscape. The main area of interest is along the west ridge of the island. Here strong ocean currents bring in some larger pelagic fish. Especially around full and dark moon it is possible to witness large schools of trevally, snapper and rainbow runners feeding on bait balls of glass fish. Koh Bon is also one of the few places to spot the endangered Napoleon Wrasse.

Manta spotting snorkelling at Koh Bon
Manta cruising at Koh Bon

Current State of Koh Bon

The Manta rays at Koh Bon certainly pull in the crowds. Scuba diving boats congregate in large numbers around Koh Bon. It can get very congested underwater. The island is almost as popular as famous Richelieu Rock for diving. At first glance it might appear that this will effect our snorkeling activities. This, however is not the case.

the beauty of our flexible snorkel liveaboard is that we can always head to more secluded spots away from the crowds

The dive boats at Koh Bon have to follow predicable schedules. Divers need time on the surface between dives and the crews need time to fill the scuba tanks. We snorkel at the times we know there will be few divers in the water. This gives us a better chance of seeing a more undisturbed environment. Snorkeling at the surface also is a commanding position to look out for manta rays. To date, Koh Bon is not a popular destination for snorkeling day trips. It is highly likely when we hit the water we will be the only snorkellers there. If more snorkel boats do arrive, the beauty of our flexible snorkel liveaboard is that we can always head to more secluded spots away from the crowds.

More about our best Snorkelling Destinations

Snorkel Destinations

Andaman Snorkel Discovery’s snorkel liveaboard offers you the chance to snorkel Thailand’s best destinations. Thailand in general is a great location for snorkelling. Both in the Andaman Sea and the Gulf of Thailand. Warm, clear waters are teeming with exotic tropical fish. There are colourful corals and seafans forming wonderful underwater scenes.

Surin Islands

The Surin Islands are often over shadowed by their famous neighbours, the Similan Islands. For snorkelers the Surin Islands actually have a lot more appeal. Beneath the warm, shallow waters that surround the islands, there are extensive coral reef ecosystems. The Surin Islands have made a name for themselves as the best Thailand snorkel destination.

Koh Tachai

Koh Tachai is the most northerly island before you reach the Surin Islands. Like the Similan Islands, huge granite boulders, dense tropical rainforest dominate the scene, surrounded by the turquoise warm waters of the Andaman Sea. The beach at Koh Tachai is the most beautiful in all of the Similan National Park.