Richelieu Rock (called ''Hin Plo Naam'' in Thai) is a dive site in

Thailand Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...

in the

Andaman Sea The Andaman Sea (historically also known as the Burma Sea) is a marginal sea of the northeastern Indian Ocean bounded by the coastlines of Myanmar and Thailand along the Gulf of Martaban and the west side of the Malay Peninsula, and separated f ...

about from the mainland. It is part of the Mu Ko Surin National Park although being about east of Ko Surin Tai. There are no islands in the immediate vicinity of the reef. The limestone pinnacle rises from the sea floor of about above the surface at low tide. The horseshoe-shaped reef is known for its purple corals as well as diverse marine life ranging from small fish and harlequin shrimp to large pelagics like

whale shark The whale shark (''Rhincodon typus'') is a slow-moving, filter feeder, filter-feeding carpet shark and the largest known Extant taxon, extant fish species. The largest confirmed individual had a length of . The whale shark holds many records for ...

and

manta ray Manta rays are large Batoidea, rays belonging to the genus ''Mobula'' (formerly its own genus ''Manta''). The larger species, ''Giant oceanic manta ray, M. birostris'', reaches in width, while the smaller, ''Reef manta ray, M. alfredi'', reac ...

Discovery and name

It was named after Admiral Richelieu, a commander in the

Royal Thai Navy The Royal Thai Navy (Abbreviation, Abrv: RTN, ทร.; , ) is the Navy, naval warfare force of Thailand. Established in 1906, it was modernised by the Admiral Prince Abhakara Kiartiwongse (1880–1923) who is known as the father of the Royal N ...

, supported by the existence of official Navy maps mentioning Richelieu Rock from the early 1900s. Richelieu was the first person to complete a hydrographic survey of the

including the area in question. Some – falsely – state that Richelieu Rock was discovered as a

recreational diving Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasur ...

site by diving pioneer,

Jacques-Yves Cousteau Jacques-Yves Cousteau, (, also , ; 11 June 191025 June 1997) was a French naval officer, oceanographer, filmmaker and author. He co-invented the first successful open-circuit self-contained underwater breathing apparatus (SCUBA), called the A ...

, with the help of local fishermen and was named by him after the red colour of

Cardinal Richelieu Armand Jean du Plessis, 1st Duke of Richelieu (9 September 1585 – 4 December 1642), commonly known as Cardinal Richelieu, was a Catholic Church in France, French Catholic prelate and statesman who had an outsized influence in civil and religi ...

's robe due to the red to purple colours of the

soft coral Alcyonacea is the old scientific order name for the informal group known as "soft corals". It is now an unaccepted name for class Octocorallia. It became deprecated . The following text should be considered a historical, outdated way of treatin ...

s on the reef. However, on his

Andaman Andaman may refer to: * Andaman Islands, an island group in the Bay of Bengal * Andaman Island, Penang, an artificial island in George Town, Penang * Andaman Sea, a sea of the eastern Indian Ocean * ''Andaman'' (1998 film), an Indian Kannada-lang ...

expedition in 1989 he came only as far north as Koh Bon in the

Similan Islands The Similan Islands (, , , Malay: ''Kepulauan Sembilan'') is a continental archipelago in the Andaman Sea off the coast of, and part of, Phang Nga Province in southern Thailand. It is the maritime border between India and Thailand. It was es ...

whilst waiting a permit for

Myanmar Myanmar, officially the Republic of the Union of Myanmar; and also referred to as Burma (the official English name until 1989), is a country in northwest Southeast Asia. It is the largest country by area in Mainland Southeast Asia and has ...

(which was never granted).

Marine life

Partly due to its unique geology as a solitary pinnacle standing out from around depth to just under the surface at high tide it attracts a variety of different pelagic species of all different sizes. Reports claim regular appearance of

Malabar grouper The Malabar grouper (''Epinephelus malabaricus'') also known as blackspot rockcod, estuary rockcod, giant rock cod, greasy grouper, Malabar rockcod, Morgan's cod or speckled grouper, is a species of marine ray-finned fish, a grouper from the subf ...

bigeye snapper The bigeye snapper (''Lutjanus lutjanus''), also known as the bigeye seaperch, red sea lined snapper, golden striped snapper, rosy snapper, yellow snapper, or simply snapper, is a species of marine ray-finned fish, a snapper belonging to the fa ...

s, Bannerfish,

lionfish ''Pterois'' is a genus of venomous fish, venomous marine fish, commonly known as the lionfish, native to the Indo-Pacific. It is characterized by conspicuous aposematism, warning coloration with red or black bands and ostentatious dorsal fins tip ...

triggerfish Triggerfish are about 40 species of often brightly colored marine ray-finned fishes belonging to the family Balistidae. Often marked by lines and spots, they inhabit tropical and subtropical oceans throughout the world, with the greatest speci ...

es and shovelnose rays. While sightings are rare, February to April is the best time to spot large pelagic species like

s and

s. Richelieu Rock is also well known for its large variety of small and rare marine critters, such as

sea horses A seahorse (also written ''sea-horse'' and ''sea horse'') is any of 46 species of small marine bony fish in the genus ''Hippocampus''. The genus name comes from the Ancient Greek (), itself from () meaning "horse" and () meaning "sea monster ...

frogfish Frogfishes are any member of the anglerfish family Antennariidae, of the order Lophiiformes. Antennariids are known as anglerfish in Australia, where the term "frogfish" refers to members of the unrelated family Batrachoididae. Frogfishes are f ...

harlequin shrimp ''Hymenocera picta'', commonly known as the harlequin shrimp, is a species of saltwater shrimp found at coral reefs in the tropical Indian and Pacific Oceans. It is usually considered the only species in the genus ''Hymenocera'', but some spli ...

pineapplefish The pineapplefish (''Cleidopus gloriamaris'') also known as the Mailfish is a species of fish in the family Monocentridae, and the sole member of the genus ''Cleidopus''. It is also known as the knightfish or the coat-of-mail fish, due to the ar ...

, orang utang crab and several other species of crabs and shrimp.

Dive site

Richelieu Rock is considered to be one of Thailand's most iconic dive sites. It is usually accessed by live-aboard diving boats during cruises, as it is too far off the coast to be reached by usual dive boats, though there are speedboats that can go to Richelieu Rock as a daytrip. Richelieu Rock is part of the Mu Ko Surin National Park, which is open 15 October to 15 May and may close earlier depending on weather conditions.

References

External links

{{Wikivoyage inline, Diving in Thailand/Richelieu Rock, Richelieu Rock
Richelieu Rock dive map
Andaman Sea Tourism in Thailand Diving in Thailand