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Similan Island, Koh Bon & Koh Tachai

Day Trips with 2 or 3 dives
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Dive Sites

A Guittar Shark family (Video: Nattapong Nilsawit)

Similan Islands


Dive Sites

Due to the corona crisis, we have to cancel the 2020/21 season and hope that we can continue next year ...

Here are some of the most beautiful and diverse dive sites in Thailand, day trips and liveaboards to the islands are among the most popular worldwide. They consist of nine islands of granite rock with partially lush tropical vegetation, lapped by crystal clear water and lined partly with fine white sandy beaches. The islands stretch over 25 kilometers, like a pearl necklace, from north to south on the Andaman Sea and located 65 kilometers off the coast of Phang Nga province. They were declared a Marine National Park in 1982.

The Similans are ideal for observing or photographing small fish by its enormous biodiversity of tropical reef fish. But not only small fish visit here, even Leopard sharks or White and Blacktip sharks are not rare also Manta rays and Whale sharks can be seen. You can visit the Similan Marine National Park from October to May on day trips or overnight trips, but you will find the best conditions from November to April.

Our guests are picked-up at the hotel and then taken by taxi to our pier in Nam Khem, north of Khao Lak.
(see schedule below)

Rules for the Similan National park

1. For bookings, we need the first name, family name, nationality, date of birth and passport number
2. For divers also: dive level, number of logged dives,
date of the last dive & dive certificate
3. Visitors must carry a copy or picture of their passport with
4. Drone flights are strictly prohibited
5. Beginner’s courses (Try Dives, OWD) are not allowed – only at Surin Islands and local dive sites
6. Single-use plastic is not allowed to take
7. Stay overnight is not allowed anymore
8. Bookings or cancellations have to be done latest 5:00 pm, the before the trip starts

Since there are only 525 tickets per day for the Similan National Park, we strongly advise you to book tours well in advance - especially for diving packages!


Manta Ray at Koh Bon

Table Coral with Fish School

Gorgonia Sea Fan

Manta Show Koh Bon

Koh Bon


Manta Ray at Koh Bon

Koh Bon is located about 20 kilometers north of Similan Island #9 and features one of the only vertical walls in Thailand. The main dive site is on the southwestern point and has a step-down ridge that carries on to depths of over 45 meters. The eastern side of this ridge forms the wall and this is where most divers will enter the water and generally where the boat moor.

The western side of the ridge is more of a gentle slope with coral bommies forming mushroom-like formations out of the finger corals. On the ridge itself, sea fans of different sizes, shapes and colors grow, and schooling fish swim in the current feeding. This is generally where most divers will sit most of the dive, hoping for a sighting of the manta rays which frequent visit this dive site. These creatures seem to travel from Bon to Tachai and back again during the diving season from October until May.

There is a pinnacle in the bay just to the north of the ridge. It's a deep rock but if you are an experienced diver it's worth the short bottom times you'll get as it's a very special site. Not all boats visit it and if conditions are not good (like the current is running strong), it's not worth the effort. But if the water is clear you're good with your air and the current is slack it's a stunning rock. It looks like a monolithic temple built by some ancient culture.


Koh Tachai

Feather Star

Sun Mushroom Coral

Fish Fish Fish ...

Koh Tachai


Koh Tachai

Twenty-five kilometers north of Koh Bon, Koh Tachai has an offshore underwater ridge that runs perpendicular to the island. Known as "Twin Peaks" this is considered to be one of the finest dives in the Kingdom of Thailand and is famous as a place to see not only the more common species of corals, fans and tropical fish, but larger animals such as rays, leopard sharks, nurse sharks and hawksbill turtles. Whale sharks and Manta rays make an appearance on a regular basis.

A ridge runs between the two pinnacles, though the southern rock is the one most people dive on as there are two boat moorings there which makes it easier for divers to descend in a strong current. If you have the air and the current is not too strong, it's worthwhile swimming to the other rock which comes up a bit shallower. However, most of the time the current runs perpendicular to the ridge making a long swim tiring.

It's heaven for the fish, though; they hunt and dart around, coming very close to divers, making the diving here about as exciting as it gets here in Thailand

Schedule from 1. November to 30. April

Monday Similan Island # 9 for divers & snorkelers - 2 dives
Tuesday Richelieu Rock for divers only - 2 dives
Wednesday Koh Tachai & Koh Bon for divers only - 3 dives
Thursday Richelieu Rock for divers only - 2 dives
Friday Similan Island # 7 for divers & snorkelers - 2 dives
Saturday Koh Tachai & Koh Bon for divers & snorkelers - 2 dives
Sunday Richelieu Rock for divers only - 2 dives

Due to the expected travel restrictions, we will probably not go according to the schedule in the coming season. We plan day tours from the end of October on every weekend (especially on long weekends in connection with public holidays)
Please send inquiries by email to:

Our High-speed Catamaran will take you comfortably and fast to the Similan Island #7 or #9, Koh Tachai & Koh Bon &. The regular schedule applies between the 1st of November and mid-April. Before and after that, we try to run a trip every second day to the Similan Islands or Koh Bon - depends on weather and inquiries.

Trips to the Richelieu Rock



Tigertail Seahorse

Christmas Tree Worm

Moray Eel in a coral


Daily Schedule



Pick-up at your hotel between 7:50 and 8:45 am - depends on the location. Our High-speed Catamaran CHARONIA departs from
iQ-DIVE Pier in Baan Nam Khem at 9:00 am.

We arrive at
Similan Islands around 10:45 am
Koh Tachai around 10:15 am
Koh Bon (2. dive) around 1:00 pm

Now, we conduct our first diving or snorkeling with our professional guides and right after that, we will have a 90 minutes lunch break onboard. After that, we prepare for our second diving or snorkeling.
We will be back at the pier between 3:00 and 4:00 pm - depends on the dive destination - Wednesdays around 6:30 pm because we're doing 3 dives.
Our Taxi will take you back to your Resort.

Pick-up times
Lam Kaen: 07:50 am
Nang Thong: 08:00 am
Bang Niang: 08:05 am
Khuk Khak: 08:15 am
Pakarang: 08:25 am
Pak Weep: 08:25 am
Bang Sak: 08:35 am
Nam Khem: 08:45 am

We are happy to arrange as well day trip tours for snorkelers by speed boat to the Similan or Surin Islands.

Furthermore Speedboat Charter for dive or snorkel trips

Day Trip Prices

Day trip Similan or Koh Tachai & Koh Bon 2 dives 4.800,-
Day trip Surin Island or Richelieu Rock 2 dives 4.800,-
Day trip Koh Tachai & Koh Bon 3 dives 5.800,-
Snorkeler Adult 2.800,-
Passenger Adult 2.500,-
Snorkeler / Passenger child (5-12 years) 2.200,-
Minimum age 5 years

All prices in Thai Baht (THB)
Easy to pay with PayPal

Price includes
Travel Insurance, Transfer from Khao Lak hotel-boat-hotel, lunch, drinking water, soft drinks, fruits, towel, mask and snorkel, fins, life jacket, guide, and liability insurance, NITROX
(There is no right to a refund if Nitrox is not available!)

Not included
National Park entry fee adult per day 500 THB + diving fee 200 THB
Entry fee children per day 300 THB + diving fee 200 THB

Rental equipment per day
BCD 200 THB, regulator 200 THB, shorty 3mm 100 THB,
Dive computer 250 THB, LED Flashlight 200 THB, Compass 150 THB

Since there are only 525 tickets per day for the Similan National Park, we strongly advise you to book tours well in advance - especially for diving packages!