Welcome to Koh Tachai Pinnacle
If you are on a Similan Liveaboard you will probably not reach Koh Tachai until day 2 or 3, so you will have time to refresh your diving skills beforehand. If you visit Koh Tachai pinnacle on a day trip, then you would ideally need to have dived fairly recently. This can be a challenging dive.
The entry is the most important part of the dive. If you get it right then it will make the rest of the dive much easier. There is one mooring line attached to the top of the main pinnacle. You should be dropped off so the current is pushing you towards the line. Before you jump in take a look at where the buoy line is. After you jump, get your bearings again, then look for the big orange buoy.
Buddy up, follow your instructor, and begin to descend. Sometimes it will be possible to descend right onto the top of the pinnacle. Other times you will need to make sure you grab the line as you start to drift past it. Pull yourself down the line until you reach the top of the rocks. Once you are on the dive site then stay close to the boulders and use them as protection against the current.
To see a large portion of the dive site it is best to go to your deepest point first and spiral your way back up to the top of the pinnacle. Sometimes the current will be in your favour and other times you will need to swim against it. You can dive to 30m but this is not always the best idea. You will use your air much quicker, run out of no decompression time, and have a much shorter dive. As most of the activity is closer to the top of the pinnacle, it is not necessary to stay deep for a long time. Staying between 15m-25m can make for a longer and more enjoyable dive.
The Marine life is very diverse. The healthiest corals are the soft corals, particularly the large sea fans. The fish range in size from the tiniest glass fish to Giant Trevally and big marbled groupers. You can find Barracuda, Batfish, fusiliers, rainbow runners, Tuna, Triggerfish, and more. Manta Rays can be seen just as regularly here than at Koh Bon and Whale Sharks could pass by any time of the year. If you insist on looking for small things, you can find nudibranchs and other little critters, but we suggest you turn around and check out what is swimming over your head. Save the macro diving for Richelieu Rock.
If you have the chance to do more than one dive here, then there are many areas to explore. The main pinnacle is big enough for a few dives, but you can also go up to the less visited North pinnacle or even the small coral garden on top of the large boulder in the far North West. Richelieu rock may be the most beautiful dive site in Thailand, but Koh Tachai Pinnacle is the most exciting.