Koh Rok Diving

The Koh Rok islands, nestled in the Andaman Sea off the south coast of Koh Lanta, are a hidden gem for divers seeking pristine underwater landscapes and abundant marine life. Not many dive shops visit these islands, so diving at Koh Rok is pretty special.

Comprising two small islands, Koh Rok Nai and Koh Rok Nok, this diving paradise is part of the Mu Koh Lanta National Park.

Koh Rok offers clear turquoise waters, stunning beaches, and vibrant coral gardens teeming with life. These dive sites are easily reached by speed boat from Koh Lanta.

We also love taking student divers to Koh Rok, which is suitable for most courses and experiences, including introduction dives, open water diver courses, and the rescue diver course.

With excellent visibility and gentle currents, Koh Rok is an excellent destination for all levels of certified diver.

Koh Rok Marine Life

Marine Protected Area

Koh Rok’s protected status as part of the Mu Ko Lanta National Park has allowed its marine ecosystem to flourish.

The nutrient-rich waters around the islands support a diverse range of marine life, from colourful reef fish to larger pelagic species.

Find out more from the Thailand Department of National Parks on the Mu Koh Lanta Marine National Park.

Corals & Anemones

The coral reefs at Koh Rok are some of the most vibrant and well-preserved in the region.

Divers will find an array of hard and soft corals, including giant gorgonian sea fans, brain corals, staghorn corals, mushroom corals, and extensive fire coral gardens.

Giant clams are scattered throughout the coral reefs, and carpet anemones and clownfish are abundant at all dive sites around Koh Rok.

These coral formations create a complex underwater environment that provides shelter and sustenance for a multitude of marine species.

Fish Species

Koh Rok is home to a wide variety of fish species, making it a popular spot for underwater photographers and marine enthusiasts. Commonly seen species include parrotfish, lizardfish, crocodile needlefish, cornetfish, angelfish, butterflyfish, batfish and triggerfish.

Small schools of convict Surgeonfish are often seen around Koh Rok Nai at Lak Siam and Hin Ngam, the only dive sites where we can spot this species.

Schools of fusiliers, snappers, and barracudas are frequently spotted swimming around the reefs. In addition to these, divers may also encounter moray eels, groupers, and the occasional blacktip reef shark patrolling the area.

Macro Life

For those interested in the smaller inhabitants of the reef, Koh Rok offers an abundance of macro life.

The coral gardens are teeming with nudibranchs, flatworms, Christmas tree worms, and various species of shrimps and crabs.

Seahorses, pipefish, and frogfish can also be found hiding among the corals, making Koh Rok a favourite destination for macro photography.

Larger Marine Life

While Koh Rok is primarily known for its rich coral reefs and reef fish, divers may also have the chance to see larger marine species.

Critically endangered hawksbill turtles are often seen grazing along the reef, particularly at Lak Siam.

Occasionally we have spotted eagle rays and whale sharks passing through the area around Hin Ngam and the southern part of Lak Siam, adding to the excitement of diving at Koh Rok.

Exploring Koh Rok: Hin Ngam

Diving Koh Rok from Koh Lanta

Hin Ngam is located at the south west part of Koh Rok Nai and is a rocky dive site with an abundance of hard and soft corals.

Koh Rok: Hin Ngam Plateau

The dive starts at a bay in the south west part of Koh Rok Nai, following the reef on the left shoulder. The shallows begin with large boulders, becoming smaller with depth, eventually revealing a gently sloping reef from around 7 - 8m down to 18m +.

This is a great area for marco life such as shrimp and nudibranchs, and for larger species of sea cucumber, angelfish, surgeonfish, moray eels and turtles.

You will find hard corals, including boulder corals and branching corals, soft corals, including sea whips, anemones, clownfish and many other species in this area. If you are very lucky, you may spot a marble ray, guitar sharks, eagle rays or possibly the occasional whale shark in this area.

As you continue eastward you find larger rocks and boulders, bubble corals, hard coral bommies surrounded by whip corals, giant barrel sponges, glassfish, fusiliers, groupers, surgeonfish and moray eels.

Koh Rok: Hin Ngam Deep Corner

Eventually the reef slope becomes more steep, strewn with bubble corals and barrel sponges, gradually becoming a steep wall in deeper areas.

The imposing rock face forms an underwater ridge, creating a dramatic natural geological barrier which marks the end of the first sloping reef, and the start of the second sloping reef as we turn the corner and enter the next bay.

Around the rocky ridge we find substantial coral bommies in the sandy areas, and in deeper parts, we can see larger fish, including the giant potato grouper, up to 1.5 - 1.8 metres in length.

Koh Rok: Hin Ngam Shallow Bay

After the huge rocky finger, we again find ourselves on a broad sloping reef, more rocky in the shallows. Large stingrays can be seen resting in sandy patches between the coral formations.

There is a great abundance of sea whip corals in the shallower areas. Batfish, angelfish, wrasse, parrotfish, sweetlips, surgeonfish, snapper and turtles can all be found here. The shallow area here is also great for snorkelling.

Hard and soft corals are found at all depths, and we end the dive in the shallows where we can sometimes spot hawksbill turtles.

Koh Rok: Hin Ngam Dive Site Guide

• NameKoh Rok - Hin Ngam
• Visibility10m - 20m +
• Level of DivingAll Levels
• SnorkelingYes
• Depth1m - 25m +
• CurrentsMild to Medium
• Journey Time50 - 60 mins

Exploring Koh Rok: Lak Siam

Diving Koh Rok from Koh Lanta

Koh Rok: Lak Siam Fire Coral Garden

Lak Siam is a long and extensive reef area running almost the entire east coast of Koh Rok Nok. The sandy beach is fringed with a huge area of fire corals which makes this a super snorkelling spot at Koh Rok.

As we head a little deeper we encounter a sloping coral reef down to around 15 - 20 metres and runs the entire length of the east side of the island. The snorkelling here is as good as Koh Haa Lagoon.

Koh Rok: Lak Siam Sloping Reef

Dropping in the middle of Lak Siam, we can either dive with our right, or left shoulder to the reef. The sandy slope is covered extensively with a huge variety of hard and soft corals, creating a dense and rich coral reef.

The sloping reef is home to a huge variety of corals, including branching corals, bubble corals, mushroom corals, lettuce corals, anemones, brain corals, leather corals, soft corals and sea fans.

The dense corals are home to millions of reef fish, including moorish idols, snapper, fusiliers, grouper, wrasse, moray eels, angelfish, butterfly fish, clownfish, shrimp, sea cucumbers, snails, slugs, urchins, feather stars, surgeonfish, parrotfish and many, many other species.

We can also find several species not commonly seen around our other dive sites, such as the convict surgeonfish and more rare species of butterflyfish and angelfish.

Here you will definitely find nemo.

Diving with Turtles

Along the deeper fringes of Lak Siam we find an almost continuous line of giant gorgonian sea fans, giant barrel sponges, and bubble corals, the favourite food of the many turtles which we often see along this reef. Indeed, it is unusual not to see at least one or two turtles on this dive, sometimes more.

Koh Rok: Lak Siam South Bay

The southerly part of Lak Siam becomes a more rocky slope and it approaches the shallower end point of the Hin Ngam dive. There is a wide shallow bay around 5 - 9 metres deep, dropping off steeply to around 22 metres.

The shallower area is characterised by large round rocks encrusted with both hard and soft corals, and is home to stingrays, surgeonfish, feather stars, damselfish.

Barrel sponges and sea fans are abundant in this area, along with sea cucumbers and many sea stars in the shallows around 5 - 6 metres.

Koh Rok: Lak Siam Dive Site Guide

• NameKoh Rok - Lak Siam
• Visibility10m - 30m +
• Level of DivingAll Levels
• SnorkelingYes
• Depth1m - 18m +
• CurrentsMild to Medium
• Journey Time50 - 60 mins

Exploring Viewpoint & Pak Rong

Diving Koh Rok from Koh Lanta

Entry to this dive site is in a small bay to the far west of Koh Rok Nai at the entrance channel between the two islands (Pak Rong) where we drop down over rocks and hard corals to a maximum depth of 18 m and head north with the reef to our right shoulder.

A small wall develops on our right shoulder, and as we approach the north west corner over hard corals, we find a finger reef around 12 m with soft corals and a chance to spot stingrays around the reef.

We can expect to see pufferfish, octopus, clownfish, triggerfish, sea snakes, moray eels, shrimp and lobster during this dive.

A large bed of broken staghorns corals has collapsed to provide shelter for many large Brown marbled Groupers around 12 m. There are many large rocks on the bottom and as we approach the end of the dive we find a lot of hard corals including lettuce corals in the shallows.

Large schools of yellow snapper, schools of moorish idols and white collar butterflyfish are often seen during this dive.

Snorkelling is on the opposite side of the channel at Pak Rong on the northeast tip of Koh Rok Nok.

Koh Rok: Viewpoint Dive Site Guide

• NameKoh Rok - Pak Rong
• Visibility10m - 20m +
• Level of DivingAll Levels
• SnorkelingYes
• Depth3m - 18m +
• CurrentsMild to Medium
• Journey Time50 - 60 mins

Koh Rok Diving Price

Koh Lanta Dive Trips

Fun Diving price at Koh Rok is ฿3,150 for 2 dives. Diving price includes dive guide, free equipment rental, lunch & soft drinks on the boat when booked online in advance.

• You must be certified minimum SSI/PADI Open Water Diver, CMAS 1 Star Diver, BSAC Ocean Diver, or equivalent.
• Scuba Skills Refresher for extra ฿900 when Booked Online (Normal Price ฿1,000).
• Does not include Marine Park Diving Fee: Thai ฿240, Foreigner ฿600, per day.

See a complete list of all our Koh Lanta Diving Prices.

Koh Lanta Dive Sites

Some of Thailand's Best Diving

Koh Rok is one of the best dive sites in Thailand, and can be easily dived from Koh Lanta by speedboat along with many of Thailand's other top dive sites:

Find out more at the Thai Department of National Parks.

Our Dive Trip Schedule

Lanta Dive trips from 15 Oct - 15 May

Our dive trips depart Koh Lanta in the morning every day during high season from the south end of Long Beach, normally returning around 1:30 - 2pm.

• All trips are 2 dives a day
• Trips depart from the beach at our dive shop @ Lanta Castaway Beach Resort
• Trips Depart 8/9am, return 2pm
• Dive & Relax is open from Oct 15 - May 15.
• E-mail us info@diveandrelax.com in advance with any questions, or to make a booking.

We may schedule a Shark Point & Anemone Reef dive trip or a KledKaeo Wreck & Hin Klai dive trip upon request. A minimum of 5 divers are required for these trips, please let us know if you are interested.

We love to dive as much as possible during the high season, however all our dive trips depend on the weather, sea conditions, currents and minimum numbers and may be subject to change at short notice.

For more information on our weather and climate, check out the best time to visit Koh Lanta.