The Best Dive Sites Around the Similan Islands

If you’re dreaming of diving in Thailand, chances are the Similan Islands are already on your list. Picture crystal-clear blue water, granite boulders the size of houses, and schools of fish that look like they’re auditioning for Finding Nemo 3.

But the magic doesn’t stop there. Just a little further north, the Surin Islands are home to some of the most legendary dive sites in the world. Whether you’re visiting on a scuba diving day trip or joining a liveaboard adventure, here are the best dive sites around the Similan and Surin Islands that you absolutely don’t want to miss.

Quick answer: The best dive sites around the Similan and Surin Islands are Richelieu Rock (Surin), Thailand’s top site for whale sharks and macro life, plus Aow Pakkad, West of Eden, Tuna Wreck, Three Trees, North Point, Koh Tachai Pinnacle, Koh Bon West Ridge (the manta cleaning station) and Christmas Point. The Similan sites offer granite boulders and swim-throughs, while the Surin sites add Richelieu Rock and northern reefs. Reach them on a day trip from Khao Lak or, for the remote northern sites, a 3 to 5 day liveaboard.

🐋 1. Richelieu Rock (Surin Islands)

Let’s start with the big one: Richelieu Rock. It is hands-down Thailand’s most famous dive site and for good reason. This pinnacle rises from the depths and is covered in soft corals, sea fans, and sponges in every shade of purple and red. You’ll find everything here: harlequin shrimp, ghost pipefish, cuttlefish, and seahorses. Plus the occasional whale shark cruising by. It’s basically the underwater version of a celebrity red carpet.

🪸 2. Aow Pakkad (Surin Islands)

A hidden gem up in the Surin Islands, Aow Pakkad (or “Cabbage Bay”) is a vibrant coral garden famous for its layers of lettuce corals and dense fish life. The site is teeming with schools of snapper, fusiliers, and the occasional bumphead parrotfish passing through. It’s a calm and colorful dive that shows off just how healthy Thailand’s northern reefs can be.

🪞 3. West of Eden (Similan Islands, Island 7)

This site is a photographer’s dream. A mix of giant granite boulders, coral gardens, and swim-throughs. West of Eden has a bit of everything: from macro critters like nudibranchs and shrimp to big pelagics patrolling the blue. It’s one of the most popular and well-balanced dives in the Similans.

⚓ 4. Tuna Wreck (Similan Islands)

For a change of scenery, dive into Tuna Wreck. An artificial reef just off Island 5. The small wreck sits at around 30 meters and is now home to schools of snappers, lionfish, and even the occasional giant moray eel. It’s a fun site for experienced divers who love exploring a bit of history along with their corals.

🌿 5. Three Trees (Similan Islands, Island 9)

Named after the trio of trees that mark the beach above, Three Trees is a beautiful site with a sandy slope that gives way to coral bommies and deeper granite formations. Expect garden eels, stingrays, and sometimes a passing eagle ray. It’s one of those dives where you can start relaxed and end with a bit of adventure.

🐠 6. North Point (Similan Islands, Island 9)

A personal favorite among dive pros, North Point combines deep swim-throughs, soft corals, and the chance to spot bigger creatures like white-tip reef sharks and Napoleon wrasse. The deeper sections are decorated with sea fans and whip corals that make you feel tiny in the best possible way.

🦈 7. Koh Tachai Pinnacle

Dramatic, wild, and teeming with life Koh Tachai Pinnacle is one of the most thrilling dives in the area. Strong currents attract schools of barracuda, trevally, and sometimes even manta rays and sharks. It’s a site for confident divers who love that adrenaline rush of drifting through blue water with big fish all around.

🐡 8. Koh Bon West Ridge

If you came to Thailand hoping to meet mantas, this is the spot. The cleaning station at Koh Bon West Ridge is manta central, graceful giants often circle here for ages while cleaner wrasses do their thing. The ridge itself drops off into the deep, with colorful soft corals and tons of schooling fish.

🎄 9. Christmas Point (Similan Islands, Island 9)

Don’t let the festive name fool you. There are no Christmas trees here, but there are incredible underwater landscapes. Huge granite arches, dramatic swim-throughs, and coral gardens make Christmas Point one of the most scenic sites in the Similans. Keep your eyes peeled for reef sharks, rays, and swirling schools of snapper.

Similan Dive Sites FAQ

What is the best dive site in the Similan and Surin Islands?

Richelieu Rock in the Surin Islands is widely considered Thailand’s best dive site. The pinnacle is covered in soft corals and sea fans and holds macro life such as harlequin shrimp, ghost pipefish and seahorses, with occasional whale sharks passing by.

Where can you dive with manta rays in the Similans?

Koh Bon West Ridge is the top manta spot. It has a cleaning station where mantas often circle for long periods, and Koh Tachai Pinnacle also draws mantas along with barracuda and trevally in strong currents.

Are there any wreck dives in the Similan Islands?

Yes. Tuna Wreck off Island 5 is a small artificial reef sitting at around 30 meters, now home to snappers, lionfish and the occasional giant moray eel. It suits experienced divers comfortable at that depth.

Can you dive Richelieu Rock on a day trip?

Richelieu Rock is far north near the Surin Islands and is usually a liveaboard site, but it can be reached comfortably as a day trip from a private pier north of Khao Lak. For the full remote circuit including Koh Bon and Koh Tachai, a liveaboard is best.

🐠 Day Trip or Liveaboard: Which Should You Choose?

If you’re short on time or new to diving, a day trip from Khao Lak is perfect. You’ll hit some of the top Similan sites and still make it back for sunset cocktails. That said, for day trips: we’ve got you covered like no one else. Thanks to our private pier north of Khao Lak, we’re closer to the Surin Islands and world-famous Richelieu Rock, meaning we can reach these incredible sites comfortably as a day trip.

If you want to see it all and dive places like Richelieu Rock, Koh Bon, and Koh Tachai, a liveaboard is absolutely worth it. You’ll reach remote sites, do up to four dives a day, and wake up each morning surrounded by turquoise water and the smell of coffee brewing on deck. It’s the ultimate diver’s dream.

In short:
The Similan and Surin Islands together offer everything from gentle coral gardens to whale shark encounters. Whether you’re in it for macro life, swim-throughs, or just that weightless feeling under the Andaman sun: this is Thai diving at its very best. To time it right, read up on the best time to visit and what marine life you can see.

Ready to dive these sites? Book a Similan and Surin day trip or message us on WhatsApp and we will tailor the trip to your level.