Similan Islands · Thailand · Pinnacle · Pelagic & blue water
Koh Tachai Pinnacle
Mantas and a swirling barracuda vortex over a current-swept plateau
Photo: luluchouette · CC BY 4.0
Koh Tachai Pinnacle is a submerged reef just south of Koh Tachai, a rocky pinnacle with a flat, coral-topped plateau surrounded by boulders and sand. Its strong currents often bring in big pelagic fish, and it is dived along with Koh Bon and Richelieu Rock on most liveaboard itineraries.
Also known as Ko Tachai Pinnacle, Twin Peaks.
Where it is and how deep
9.0575° N, 97.8125° EApproximate position — the dashed circle shows where the site lies; your operator's briefing has the mooring.
The dive
Two mooring lines lead down: one to 27 m on the eastern side of the site and one to 17 m on the southern side. The top is a flat, dome-shaped plateau at around 13 m, covered in hard corals with coral pinnacles across it, and boulders ring the rock down to a sandy bottom that starts at about 30 m.
Mantas cruise around the pinnacles, and leopard sharks are sometimes found in the deeper sandy areas. Batfish hang in the current on top of the main pinnacle and often stay with divers through their safety stops, while big schools of trevally and a swirling vortex of barracuda work the water off the rock.
Marine life and season
- Manta rays
- Barracuda
- Trevally & jacks
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Prime | Prime | Prime | Prime | Fair | Off-season | Off-season | Off-season | Off-season | Fair | Good | Prime |
Season follows Similan Islands: The park is closed by law from mid-May to mid-October; December to April is the calm high season.
Know before you go
- Currents at Koh Tachai can be strong, which makes it one of the more advanced sites on Similan liveaboard routes.
Dive videos
Koh Tachai Pinnacle, Thailand | Strong currents😱, but great marine life🦈 · No Troubles Just Bubbles on YouTube
Questions divers ask
Can Koh Tachai Pinnacle be dived on a day trip?+
No. Speedboat day trips to Koh Tachai have been banned, so the pinnacle is reached only on liveaboard itineraries.
Sources
- Koh Tachai Pinnacle — Sunrise Divers Phuket
- Ko Tachai Pinnacle — Indepth Dive Centre Phuket
- OpenStreetMap — OpenStreetMap
Photo credits
- Close view of a dark yellow-brown angelfish with bright blue curved stripes and a white tail beside red-encrusted rock by luluchouette, CC BY 4.0, via Wikimedia Commons
More dive sites in Similan Islands
Reef
A coral-covered rock standing alone on the sand
Wreck
The 27 m liveaboard Atlantis X, bow at 16 m
Reef
Longest reef in the Similans, over 300 coral species
Reef
Big granite blocks with reef sharks and Napoleon wrasse
Coral garden
Morning light on a shallow coral garden off Ko Bangu
Reef
Granite boulder maze of swim-throughs, caverns and morays
Granite arches at the exposed north end of the chain
Drift
Strong-current ridge with soft coral gardens and big boulders
Similar dives elsewhere
Offshore granite tower where barracuda and jacks school in the blue
A current-swept pinnacle from 30 m to within 5 m of the surface
Seamount summit 2 m under the surface, coated in soft coral
Occasional whale sharks and manta over a 45 m pinnacle