Similan Dive Sites
A solitary island located 20 km north of Koh Bon, Koh Tachai islands has magnificent white sandy beaches with two interesting dive spots – southern pinnacles and Tachai Reef. Tachai Pinnacle or Twin Peak islands, are a pair of submerged pinnacles located 500 metres south of Koh Tachai and are marked by a couple of buoys.
Manta rays visit this area for feeding and circling around the pinnacles. Some divers have encountered whale sharks as well. On the outer sand bed, divers can usually see leopard sharks, sometimes three to four of them in the same dive. In addition, it is possible to find Jenkin’s rays, as well as whitetip and blacktip reef sharks here as well. Swarms of chevron barracuda, bluefin trevally, batfish, snappers, and fusiliers are common here. Exotic species in the Similans area like oceanic triggerfish can be found on the reef here too. At the top of the dome-shaped pinnacle, look into the bush coral and you may be able to find camouflaged frogfish inside. However, even experienced divers find these frogfish difficult to identify.
Koh Tachai pinnacle, (Twin Peaks) is famous for its strong current, especially during full moon and new moon (when there is no moon visible). When the current is strong, divers cannot swim around the entire rock, but only half way. Divers should use the rocks to guard themselves. Keep close to the rocks and try not to stray into mid-water, otherwise you will waste both your energy and air supply. When the current is strong, divers should use the mooring line for descending and safety stops. However, be cautious while ascending, given the high volume of boat traffic dropping and picking up divers. Discuss with dive crews your ascent point and techniques carefully before diving. Always take a safety sausage in case you drift too far from a mooring line. A suggested sequence for your dive is to descent with the mooring line and then start with the deeper part. After that, keep to the left or right side of the rocks depending on the current. Go shallower afterward until you reach the top of the dome.