Richelieu Rock Thailand Dive Guide – Best Season, Tips & Marine Life
Richelieu Rock isn’t just Thailand’s most famous dive site — it’s one of the most biodiverse underwater locations in all of Southeast Asia. Rising dramatically from the seafloor in the middle of the Andaman Sea, this submerged pinnacle attracts marine life like few other places on Earth.
As dive professionals with over 5,000 dives across Southeast Asia, we’ve explored countless world-class sites — but Richelieu Rock consistently stands out. Few places offer this level of biodiversity, dramatic underwater scenery, and sheer energy beneath the surface. It’s a dive site that demands respect, preparation, and rewards those ready for the challenge.
Whether you’re planning your first trip to Thailand or ticking off a bucket-list dive, this guide will help you make the most of your experience at Richelieu Rock — including best season, marine life highlights, dive logistics, safety tips, and packing essentials.
🎥 Want to see the dive site in action?
Watch our cinematic Richelieu Rock vlog on YouTube to experience the currents, coral gardens, and fish swarms firsthand.
Where is Richelieu Rock?
Richelieu Rock lies within Surin National Park, in the northern Andaman Sea of Thailand. It sits roughly 18 km east of the Surin Islands and about 70 km northwest of Khao Lak on the mainland.
Although often included in Similan Islands liveaboard itineraries, Richelieu Rock is technically part of the Surin archipelago and is typically accessed by speedboat from Khao Lak on a day trip.
Its isolated location is part of what makes it so special. Out in open water, this horseshoe-shaped pinnacle acts as a natural magnet for marine life, from tiny macro critters to pelagic giants.
Best Time to Dive Richelieu Rock
The main dive season for Richelieu Rock runs from October to April, when the Similan and Surin Marine Parks are open. Outside these months, the parks close to allow reefs and marine life to recover.
Water temperature: ~28 °C year-round
Visibility: Can vary dramatically depending on tides and moon cycle
Currents: Often strong; some sites are not dived at all during peak current days, even with experienced groups
Whale shark season: February to April is peak time for sightings, though nothing is guaranteed
We’ve dived Richelieu Rock in November 2024 and April 2025, and conditions were noticeably different between the two. April offered more stable weather and excellent pelagic encounters, while November had cooler mornings and more variable visibility. Planning your trip around tide tables can make a huge difference to the quality of your dives.
Marine Life Highlights
Richelieu Rock is renowned for its astonishing biodiversity — both macro and pelagic. The pinnacle is draped in purple soft corals, interspersed with vibrant hard coral bommies, and swarming with fish life.
Top sightings include:
Whale sharks (seasonally, Feb–Apr)
Manta rays cruising the current splits
Giant trevally hunting in massive swarms
Rainbow frogfish, nudibranchs, ornate ghost pipefish, shrimps
Dense carpets of soft corals and anemone gardens
We’ve logged over 20 dives at Richelieu Rock, and every single one has offered something different. One of our favourite experiences is “sitting in the split” — positioning yourself in the current at the front of the pinnacle and simply watching the show unfold as GTs circle, hunt, and the reef pulses with life.
We’ve captured these moments — including GT feeding frenzies and rare macro finds — in our Richelieu Rock vlog. If you’re keen to see what it’s really like on the dive site, beyond the logistics and theory available here, it’s worth a watch. Plus with so much action and marine life, we’re think even if you aren’t planning a trip, as a scuba lover – you’ll enjoy seeing this epic dive site in cinematic action.
Day Trips vs Liveaboards – Which is Best?
Most divers reach Richelieu Rock from Khao Lak via day trip. Speedboats make the crossing in around 1 hour 20 minutes, allowing you to dive this world-class site without committing to a multi-day liveaboard.
Day Trip Advantages
More affordable than liveaboards
Flexible — great if you’re short on time
You can choose your exact dive day based on weather & tides
Ideal for experienced divers who want targeted dives
Liveaboard Advantages
Access to early/late dives avoiding peak day boat traffic
Can combine Richelieu Rock with Similan Islands, Koh Bon & Koh Tachai
More comfortable, relaxed schedule onboard
We love liveaboards, but honestly, day trips are often the smarter option for Richelieu. You can pick the best weather window and do back-to-back dives on the site without committing to days at sea.
How to Dive Richelieu Rock (Logistics & Dive Schedule)
For our recent trips, we dived with Wetzone Divers, a professional and eco-conscious operator we highly recommend.
Typical Day Trip Schedule from Khao Lak:
- 08:00 – Depart by speedboat
Light breakfast, bananas, water & fizzy drinks provided
2 dives at Richelieu Rock
Lunch on board between dives
15:00–16:00 – Return to Khao Lak resort
Price: around 6,500 THB including marine park fees, breakfast, lunch, and diving.
Prices may vary slightly depending on season.
Booking tips:
Whale shark season (Feb–Apr) fills up fast — reserve early.
Keep an eye on tide charts when choosing your dive day.
Operators may cancel if currents are too strong for safe diving.
Dive Site Conditions & Experience Level
Richelieu Rock is suitable for intermediate to advanced divers — it’s not the place for your first dive after a long break.
Conditions to expect:
Depth: 5–35 m
Visibility: Highly variable (can be 10 m or 30 m depending on tides)
Currents: Often strong, occasionally ripping
Entry: Negative entries are common
Marine Park Rules:
No gloves- No touching or poking
- No reef hooks
Before diving Richelieu, it’s smart to do a few warm-up dives at easier local sites to dial in your buoyancy. Good trim and situational awareness are essential to avoid damaging the fragile reef.
Pro Tip: Sit in the current split at the front of the pinnacle. This is where the pelagic action happens — GTs, barracuda, and sometimes even whale sharks pass by here.
Packing Essentials for Richelieu Rock
Diving here means being ready for sun, salt, current and long boat rides. Pack smart and you’ll enjoy your day far more.
Essential items include:
SMB (surface marker buoy)
Reef-safe sunscreen
Quick-dry towel
Polarised sunglasses (rinse after boat rides)
Motion sickness tablets (provided on board but good to have)
Dry bag for valuables
Light layers for sun protection on the boat
Download our FREE Andaman Coast Pro Packing Guide
This checklist covers everything from dive kit to travel logistics and local tips — perfect for Thailand dive trips.
Equipment rental is available from most Khao Lak dive shops, but if you have your own kit, it’s worth bringing it for comfort and familiarity.
🛡 Safety & Dive Insurance
Richelieu Rock is remote, so proper dive insurance is non-negotiable.
We personally use and recommend:
🌐 DAN Europe – for comprehensive dive accident coverage worldwide.
✈️ SafetyWing – flexible travel insurance that covers nomads and long-term divers.
💡 We hold annual DAN plans and recurring monthly SafetyWing coverage — both have proven invaluable for peace of mind while diving in remote areas.
Final Thoughts – Why Richelieu Rock Is Unmissable
Richelieu Rock isn’t just another dive site. It’s a living, breathing ecosystem that humbles even the most experienced divers. Its remote location, swirling currents, and vibrant biodiversity combine to create something truly unique.
For us, even after thousands of dives across the Indo-Pacific, Richelieu remains unforgettable — a site where nature still rules and every dive writes a new story.
Want to see why we love it so much?
Watch the full Richelieu Rock dive vlog on our YouTube channel for GT swarms, macro critters, and honest dive conditions.
Download our free Andaman Coast Packing Guide for divers planning their Thailand adventure.
Check out DAN & SafetyWing for essential insurance before your trip.
Download our free Andaman Coast Packing Guide for divers planning their Thailand adventure.
Now Watch the full Richelieu Rock dive Guide
Affiliate Disclosure
Some of the links above are affiliate links, which means we may earn a small commission if you make a purchase — at no extra cost to you. We only recommend services we personally use and trust.
