Koh Bon and Koh Tachai Manta Rays – Similan Liveaboards
Koh Bon and Koh Tachai are two islands at the northern edge of the Similan park in Thailand. Koh Bon’s west ridge is the best-known manta spot in the Andaman Sea, and the Koh Tachai pinnacle draws big fish in strong current. Most Similan liveaboards dive both.
Who Koh Bon & Koh Tachai Work For
Manta Fans
Intermediate Divers
Current on the ridge
Photographers
Big-Fish Fans
Short Trips
3 to 4 nights
You Can See
Mantas and Big Fish
Manta Rays
Visit the Koh Bon ridge, mostly February to April.
Koh Tachai
A remote island with a deep pinnacle offshore.
Fish Schools
Barracuda and trevally in the current.
Whale Sharks
Seen at Koh Tachai on lucky days.
Ready to meet the mantas?
Where You’ll Dive
Koh Bon and Koh Tachai Sites
Koh Bon West Ridge
A long ridge where mantas come in. You stay low on the ridge and watch the blue.
Koh Bon Bay
A sheltered side with an easy reef, good for a second dive.
Koh Tachai Pinnacle
A deep pinnacle in open water with big fish schools and strong current.
Koh Tachai Reef
Gentler reef dives near the island.
Most trips continue north to Richelieu Rock.
Hot Picks
Liveaboards We Recommend for Koh Bon
Krishna 3
Built in 2025, for 24 guests. Similan – Koh Bon – Richelieu trips, plus South Andaman weeks.
View boat →
Raga
A 37 m steel boat, refitted in 2024, for 28 guests. Similan, Koh Bon, Koh Tachai and Richelieu Rock in 4 nights.
View boat →Koh Bon & Richelieu or Full Similan Trip?
3 Nights
Krishna 3 runs short Koh Bon – Richelieu trips focused on the big-animal sites.
4 to 5 Nights
Adds the Similan Islands themselves. See our Similan Islands page.
Life Aboard
Life Around Koh Bon
Want a special offer for Koh Bon?
Message us directly — we’ll find a February to April trip with time on the manta ridge.
Chat on WhatsAppGet Ready
Before You Book Your Koh Bon Trip
Manta Season at Hanifaru Bay, Maldives
Read more →
Certification for a Liveaboard
Read more →
Seasickness: What Actually Works
Read more →Why BookDiveBoat for Koh Bon?
Mantas follow the season and the current, so timing matters. We check which Thai boats spend time at Koh Bon and Koh Tachai on your dates, and match the trip to your experience.
FAQ
Koh Bon & Koh Tachai Questions
When is manta season at Koh Bon?
What experience do I need?
Can I see whale sharks too?
Are Koh Bon and Koh Tachai part of the Similan park?
How long are the trips?
Where do trips leave from?
Book Your Koh Bon Liveaboard
No card needed. Reply under 1 hour.
