Richelieu Rock Is Widely Regarded As One Of The Top Dive Sites In The World
Very few dive sites can match Richelieu Rock for variety, so much so that it can be a bit of a nightmare for photographers choosing which lens to take. On it’s day regarded as one of the top ten dive sites in the world and is certainly the best in Thailand and allegedly ‘discovered’ by Jacques Cousteau with the help of local fisherman. There is much debate on how Richelieu Rock got it’s name but it’s nice to think that the great man had some involvement.
Richelieu Rock is a horseshoe shaped rock that sits alone in the Andaman sea. It’s nearly 20km from the Surin Islands and almost 40km from both the mainland and Koh Tachai so it’s hardly surprising it attracts so much life. At high tide it’s completely submerged and at low tide the rock just pokes above the surface which explains its Thai name – Hin Ploo Nam (rock rising from the water).
Most Similan island liveaboards will do more than one dive here and some up to four. The horseshoe shape rock always has some shelter even if the current is at its strongest. The dive plan will depend on the strength and direction of current but we try to take in the deeper northern corner of Richelieu Rock on the first dive and profile shallower for the rest of the dives.
The drop will be near or directly on the single buoy line attached at the southeast corner. If there’s strong current you’ll hold onto the buoy line to descend or just use it as a visual reference if it’s mild. Your guide will ask you to let go around 12m and swim off in the direction of least resistant and start to explore this magnificent dive site.
The marine life jumps out at you from all directions, it’s hard to know where to look. The larger fish will be immediately obvious, different trevally species, groupers and great barracuda constantly encircle the rock waiting for one of the smaller fish to venture too far from safety and the centre of the horseshoe is usually filled with a huge school of yellow snapper. Octopus and pharoah cuttlefish are always present, the latter sometimes put on a bit of a show when the large males defend their chosen female during breeding time.
The holes, cracks and caves are what make Richelieu Rock so attractive for the smaller animals and it’s important that you take your time – remember you more than likely have more than one dive here. At the bottom of the reef we can usually find a tigertail seahorse or two and its close relative the ornate ghost pipefish. Exquisitely coloured harlequin shrimp live in the cracks but they can be tucked right up inside and very difficult to find, keep an eye out for severed star fish legs which might just lead you to their house.
Moray eels love this oasis in the sand and lots of different species including giant, yellow margin, white-eyed, zebra, honeycomb and bar-tailed make Richelieu Rock their home. Lots of different varieties of nudibranchs cling to the walls and if you’re lucky you may see the very rare and bizarre looking pinecone fish.
The rock itself is festooned with purple and red soft corals and carpets of anemones in the shallower areas near the buoy line where you’ll finish your dive. Although rare, in recent times we have seen an encouraging rise in whale shark sightings in the Similan and Surin Islands so if you hear a cacophony of tank bangers you know that one of these gentle giants or a manta ray is close by.
Richelieu Rock is often the highlight of the trip and a dive site that you’ll never forget.