Richelieu Rock
South East Asia
Thailand
£2.50
Richelieu Rock: The Cardinal's Court
Richelieu Rock is widely considered the single best dive site in Thailand. This isolated, horseshoe-shaped pinnacle rises from the deep depths of the Andaman Sea, acting as an oasis for marine life. Legend has it that Jacques Cousteau discovered the site and named it after Cardinal Richelieu, comparing the cascading red and purple soft corals to the Cardinal’s robes. While it is famous for Whale Shark sightings, seasoned divers love it for the "fish soup"—the water is so thick with glassfish and snappers that you sometimes have to wave them away just to see the reef.
Why We Chose This Sticker Design
While the Similan sticker captures the giants, this design celebrates the intricate life on the rock itself. We focused on the Pharaoh Cuttlefish, the intelligent, color-changing alien that is a permanent resident of Richelieu. It is depicted hovering among the site's signature pink and purple soft corals (Dendronephthya), which cover every inch of the limestone. We also included the dense clouds of glassfish and patrolling jacks in the background to replicate the chaotic energy of this open-ocean pinnacle.
Diving Richelieu Rock
Richelieu Rock is a horseshoe-shaped limestone pinnacle in the Andaman Sea near the Surin Islands, and it is widely regarded as Thailand's best single dive site. At high tide it barely breaks the surface, which means the entire structure is diveable, from a shallow crown at 5 metres down past 30. What sets it apart is colour: the rock is smothered in purple and magenta soft coral to a degree that makes it look artificial in photographs. It also has a reputation as Thailand's most reliable whale shark site, with the best odds in the late season around February to April. Add exceptional macro — tigertail seahorses, harlequin shrimp, ghost pipefish — and it rewards divers who slow down as much as those hoping for something enormous to emerge from the blue.
- Best time to dive
- October to May, with whale shark odds best February to April
- Difficulty
- Intermediate — exposed site with current
- Water temperature
- 27–30°C
- Visibility
- 10–30m
Top dive sites
- •The shallow crown — Soft coral colour at 5–12m, ideal for the end of a dive
- •The horseshoe bay — Sheltered pocket where macro life concentrates
- •The outer wall — Drops past 30m — where pelagics cruise past
What you’ll see
Frequently asked questions
What are the chances of seeing a whale shark at Richelieu Rock?
Richelieu is the most consistently productive whale shark site in Thailand, but it is still a chance encounter rather than a guarantee. The best-reported window is February to April, towards the end of the season, when plankton concentrations rise. Divers who spend several dives on the rock across a liveaboard trip have far better odds than someone doing a single day dive. Even when the whale sharks do not show, the site is worth the trip for the soft coral and the macro life alone — which is why it tops most Thailand dive lists regardless.
How do I dive Richelieu Rock?
Almost exclusively by liveaboard. The rock sits well offshore near the Surin Islands, north of the Similans, and it is too far for a comfortable day trip from the mainland. Most Similan liveaboards out of Khao Lak or Phuket include it, usually with two or three dives on the site so you can explore different sections. Like the Similans, it falls within the seasonal park closure, so diving runs roughly October to May only.
Is Richelieu Rock difficult to dive?
It is an exposed offshore pinnacle, so current is normal and can be strong on the outer edges, and there is no shelter if conditions pick up. That said, the horseshoe shape means there is almost always a protected side, and the shallow crown at 5–12 metres makes for a relaxed end to the dive. Most operators are happy to take Open Water divers with reasonable buoyancy, but if you are newly certified you will get more from the site with a few current dives already under your belt.
