Koh Bon Island, also known as Koh Bon West Ridge and Koh Talu, is one of the most popular dive sites in the Andaman Sea. Located 40 km from the coast of Khao Lak and 100 km from Phuket Island, it is about 1.5 hours drive northeast of the Similan Islands.
In other words, the road from Phuket will take you 3 hours (100 km by land and 40 km by sea), and from Khao Lak 2 hours (20 km by land + 40 km by sea).
Let’s make a reservation right away that we are not talking about the island of the same name, which is located 2 km from Rawai Beach in Phuket.
Koh Bon belongs to the Similan Marine National Park, which is closed to the public during the western monsoon season, from early May to mid-October.
Maximum depth 40 m, visibility up to 30 m. Diver certification level not lower than AOWD.
Koh Bon is an exceptionally diving place, as all the most impressive and worthy of attention is hidden under the water. The island itself is no more than 200 m in diameter and there is not much to see – monitor lizards and bats.
On the land side of Koh Bon, there are no sandy beaches, no residential buildings, only cliffs that rise upward. But for those who can boast of good physical shape and are not constrained in finances, we still recommend staying on Koh Bon and Richelieu Rock for at least 3 days / 2 nights.
There is a number of reasons for this:
In the area of Koh Bon and Richelieu Rock, there are many dive sites that you won’t see in a dozen dive safaris. With each dive they are strikingly different from each other, each time giving the feeling that you are here for the very first time!;
During the diving safari you will have the opportunity to see the Similan fantastic sunrises and sunsets without the huge number of people who come on day trips.
The cost of such a safari, depending on the comfort of the ship, is from 6,000 THB per day. Divers live all the time on board the safari ship, but sometimes landing on picturesque beaches is possible.
Day trip to Koh Bon diving is possible with South Siam ships at scheduled times.
Of course, diving on Koh Bon, Richelieu Rock and in general on Similans is not a visit to the aquarium, where you are guaranteed to be presented with fish according to the list of purchased tickets. But the likelihood of seeing a whale shark, manta ray, not to mention many other inhabitants of the underwater world on these dive sites, from October to May is very high.
The transparency of the water at this time in the Andaman Sea is practically the same as in the Red Sea, and in some periods, we dare say, even better!
Pinnacle Koh Bon is located 100 m northeast of the tip of Koh Bon. Safari ships, due to the range of the dive site, go there only if they visit the Similan Marine Park for at least 3 days / 2 nights. There are relatively few divers on this site, so the place is quite suitable for those who enjoy being alone.
From north to south from the top of the rock, which lies at a depth of 18 m, there are rocks with peaks at a depth of 40 and 35 m, respectively.
The whole rock, especially the upper part of it, is just a paradise for photographers, there are a lot of objects for macro shooting! It even has its own guard – Napoleonfish, who can accompany you during the whole dive.
The entry point to the water on the western slope of Koh Bon (Koh Bon West Ridge) is strictly determined by the bot leader, it depends on the direction of the current.When diving to the western ridge, be sure to watch the depth carefully.
There are two large clearings at a depth of 22 m. Anchor yourself if there is a current and look around. Here you can see large horse mackerel, schools of barracuda, reef sharks, and if you’re lucky, which happens quite often, a Manta Ray hovering right above you.
The best place to dive in the Koh Bon area is the ridge located on the west side of the island and extending to a depth of 40 m.
About 800 m northwest of Koh Bon there is an underwater cliff marked with a buoy (sometimes it is not visible due to waves or tide). It starts at a depth of 18 m and goes down to a depth of 45 m. A lot of yellow soft corals and huge sea fans grow on its surface.
The southern bay is protected from wind and waves, so safari ships come here to stay. There are always underwater currents here, their strength and direction often change. When waves hit the rocks, a downward current often appears towards the open ocean.
Marine flora and fauna
For what it is worth diving on Koh Bon and Richelieu Rock – these are huge stingrays or, as they are also called, sea devils – Manta Ray. And no matter how many times you meet them under water, an indelible experience is guaranteed. The wingspan of the manta is up to 7 m, and the body weight reaches one and a half tons.
In addition to mantas, it is quite possible to meet a whale shark on Koh Bon. It is the largest inhabitant of the Andaman Sea, it can reach a length of 13 m!
Also, you are sure to see countless other marine life: lionfish, snappers, grouper, triggers, nudibranchs, arrows, octopuses, turtles, cuttlefish. Huge colonies of soft and hard corals are home to them.
Alexander Kravchenko, founder of the DIVERSAINT dive center in Phuket:
«In November 2007 my wife and I were invited to shoot a film about the Similan Islands for 3 days. One of the first dive sites we went to was Koh Bon.
The group was small – 5 people. They dropped us off with Ferretti 680. Everyone got into a strong current at once. With a lot of experience, I overloaded and was the only one who could catch on to the plateau. The visibility was perfect, but the current was atomic, and the largest animal at a depth of 18 m was only me. Much time passed, and I realized that the dive was not standard, no one was worried about me, and the whole group was at the top. The air was approaching a critical point. I prepared for the ascent, but then a shadow hung over me. It seemed that the sun had gone down, and the shooting day was ruined. But looking up, I was just stunned! A manta ray was hanging over me – as huge as the sky itself! She hung a meter above me, you could reach her with your hand, and it seemed to me that I could not see anything else.
Suddenly this manta ray moved away, and I saw two more pairs of these large, beautiful creatures. They simultaneously performed in front of me a mysterious dance known only to them. I smiled, the mask was filling with water, one hand was on the button of the inflator, the other was on the button of the video camera. They walked me slowly to the safety stop. When ascending, I turned around with the current and almost flew my back into the open mouth of the manta ray. Barely dodging, I looked into her eyes. I thought she smiled at me goodbye. There was no limit to happiness and delight!
At that moment it became clear that we would stay here for a long time.
Do you know why manta rays have such a big mouth? Tell you a secret… She just smiles when you try to catch up with her. Never rush, you just waste your air, get tired and prevent your friends with swimming fins from watching these truly wonderful underwater birds.
We wish you much joy and unforgettable impressions while discovering this amazing and unique underwater world and everything connected with it!»
Nine pearls of the Similan archipelago
SIMILAN ISLANDS: A DIVER’S PARADISE AND BEYOND
SIMILANS – RICHELIEU ROCK DIVE SITE
SIMILANS – KOH TACHAI DIVE SITE