Similans Dive Sites – Koh Bon
Koh Bon has become well-known as THE top dive site in the Similans to encounter manta rays. These magnificent animals tend to travel up and down from Koh Bon to Koh Tachai during the Similans diving season from October until May. It is located about 20km north of Similan Island no. 9 and features a fantastic vertical wall dive. The main dive site is on the southwestern point and has a step-down ridge that carries on to depths of over 45m. The eastern side of this ridge forms the wall, the western side of the ridge is more of a gentle slope with hard corals forming mushroom-like formations. On the ridge itself, there are lots of different sized seafans, and big schools of fish swimming in the current feeding. You can dive this site as part of your Similan Islands liveaboard trip or on a 2 dive Similans day trip from Phuket.
Availability
End of October – Early May
Wednesdays and Sundays. 2 dive trip from Phuket. Certified divers only.
As part of a 2, 3, 4 or 5 day Similan Islands liveaboard trip. Certified divers only.
Visibility
10 to 30 metres
Currents
Mild to strong
Depth
35 metres
Marine Life
Manta rays, Napoleon wrasse, trevallies, batfish, jacks, snappers, brown-marbled groupers, octopus, clown anemonefish, cornetfish, boxfish, angelfish, triggerfish, moray eels, peacock mantis shrimps, nudibranchs. Occasionally whale sharks.
Andy’s Description
A great Thailand dive site and although well-known for the manta ray sightings there is always plenty to see here even when the manta rays aren’t around. Koh Bon forms part of the Similans national park but is different from the other islands as it is a limestone island where as the Similans are granite. Your Similans liveaboard will likely moor up in the bay to the south of the island where you can see the spectacular scenery of the western ridge which has a large hole from one side of the headland to the other. This western ridge is also the islands main dive spot.
The bay on the other side of the ridge has a hard coral covered bottom and is home to octopus, Napoleon wrasse, colourful snappers, rainbow runners, butterflyfish and batfish. Sometimes the current is strong so you can drift dive all the way along to the ridge. All in all a great dive site and a must-do on your Similans liveaboard diving trip in Thailand.The ridge extends in a south west direction from the island dropping steadily deeper. The limestone ridge is covered in soft corals, fans and sea whips. Very often there are large schools of fusiliers above the ridge and these are hunted by blue-fin trevallies, jacks and and great barracuda. Keep looking out into the blue for the manta rays that come in to be cleaned, occasionally you’ll see eagle rays passing by too.