If you’re staying on the idyllic Krabi coastline, you’ll find you have easy access to some of the best scuba diving sites in Thailand if not the world. Protected marine parks teeming with sea life fill the calm, clear water between castaway islands.  

Whether you want a fully-immersive liveaboard experience, or just a day trip to some of the best underwater sites in Thailand, Krabi has options for you. Dive operators dot the shore at Ao Nang and Railay Beach, so wherever you’re staying you can take advantage of the intriguing wrecks and protected marine parks in the area.

Where To Dive In Krabi

Shallow sites for beginners and long swim-throughs and cave dives for the more experienced are all within easy sailing distance of Krabi’s main beaches. We’ve made a list of the best sites around Krabi to help you choose where to begin.

1. Best For Easy Access: Ao Nang Local Islands

Just a 10-minute speedboat ride, or 40-minute long-tail ride, from Krabi’s shore, the Ao Nang Local Islands have loads of interesting dive sites. Dive operators such as The Dive Ao Nang, Sea Gypsy Divers, Railay Dive Centre and Sawasdee Divers run trips from Ao Nang and Railay Beach.

The area specialises in small sea life, so keep your eyes peeled for seahorses, neon nudibranches and pipefish. These island shallows are the perfect place for first-time divers to test the waters.

More experienced divers can spot barracuda, spiny lobsters and banded sea snakes in the variety of swim-throughs around the Local Islands. Visibility can be up to fifteen metres in calm weather, but is usually limited to 5-10 metres. Koh Yawabon has an island-long swim-through where you emerge half-way into a secret cave system underneath the island.

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Cost: 2 dives from THB 2,700 (US$ 82)
Best Time To Dive: Between February and May, when the visibility is at its highest is the best time to dive, but the islands are sheltered in a bay so diving is possible all year.

2. Best For Unique Scenery: Koh Haa Yai

Top Tip: Koh Haa Yai is a 2.5 hour boat trip from Krabi, so it’s a long day trip from Ao Nang or Railay. Staying overnight on Koh Lanta will give you a more leisurely pace and you can dive with a local outfit like Dive and Relax.

Koh Haa Yai dive site is near Koh Lanta. The area is filled with underwater caves, and the biggest is known as The Cathedral. The entrance is at around 20 metres, so advanced divers would get the most out of this site. After an exciting swim-through, you can surface inside the Cathedral cave and admire the atmospheric rock formations. 

The visibility is often over 20 metres and you might find yourself swimming alongside leopard sharks. Sometimes you can spot hawksbill turtles nibbling at kelp and colourful sholes of groupers. Whale Sharks have also been spotted in the area. The Dive Ao Nang and Railay Beach Dive Center both run to this site.

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Cost: 2 dives from THB 5,600 (US$ 170). Marine park fee THB 600 (US$ 18).
Best Time To Dive: Visibility is best between February and May, when the water is calm. Diving in April increases your chances of seeing the Whale Shark.

3. Best For A Challenge: Hin Daeng Hin Muang

Found within Mu Koh Lanta Marine Park, two isolated rocks in the open water make for an enthralling day of diving. Hin Daeng, or Red Rock, plunges into the sea and you can deep dive while manta rays glide above you. It’s a long trip from Krabi and a few dive shops, such as Railay Beach Dive Center will take you out this far, but consider spending the night on Koh Lanta for easy access.

Hin Muang, or Purple Rock, can be a slightly more challenging dive as the currents are often stronger. Tackling the dive here will reward you with Thailand’s highest vertical wall, bejeweled with a rainbow of soft coral and home to grey reef sharks and leopard sharks. Due to the advanced nature of this site, it is one of the quietest in the area.

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Cost: 2 dives from THB 3,150 (US$ 96) departing from Koh Lanta
Best Time To Dive: November to April is the best time to dive the sites near Koh Lanta. Rainy seasons runs from May to December when most dive shops in the area close.

4. Best For Diverse Marine Life: Phi Phi Islands

Top Tip: If you want to dive with an operator based on Phi Phi and get the full experience, you need to stay overnight. Accommodation is available on Koh Phi Phi Don, but Phi Phi Leh is uninhabited

Famous for the backdrop to Danny Boyle’s The Beach, the Phi Phi Islands are Southern Thailand’s most idyllic islands. Under the crystal-clear water there’s a diving playground protected by marine park status. Dive with leopard sharks at Shark Point, where these sleepy giants are more likely to hide under a rock than bite your leg off.

There is also an excellent wreck dive at the King Cruiser Site where colourful marine life has taken over a naturally sunken wreck. It’s in shallow water, so divers of all levels can experience the thrill of a wreck dive. Wall dives covered in vibrant, soft coral dot the seas between the islands.

After a day’s diving, chill out on Phi Phi’s beaches, the best in Thailand. This is Krabi’s most popular diving option, so most dive shops run day trips to Koh Phi Phi, a 40km journey from the mainland.

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Cost: 2 dives from THB 3,500 (US$ 106). Marine park fee is THB 600 (US$ 18) per day.
Best Time To Dive: Dive season runs all year at Phi Phi, but the best time to go is between February and May when the water is calm and clear.

5. Best For A Liveaboard Experience: Similan Islands

Ranked as one of the top diving destinations in the world, the Similan Islands are worth several days of discovery, and are the perfect liveaboard option. Cruises generally last four days and depart from Khao Lak, a 90-minute drive from Krabi, though Stingray Divers and Aqua Vision go from Ao Nang. Once on board you’ll spend your days diving the best sites in Thailand.

Generally currents are weak and visibility is high, so you’ll see hard and soft coral clinging to rocky outcrops for miles. Underwater fauna, big and small, fill the reefs between the islands. Manta rays, leopard sharks and sea turtles patrol the waters, while macro nudibranchs, pipefish and ribbon eels cling to the rocks.

The area is also known for whale sharks, and spending more than a day diving seriously increases your chance of spotting these majestic creatures. At the end of a long day diving, relax with a sundowner on deck and dinner cooked up by a local Thai chef before waking to another day of diving in paradise.

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Cost: From THB 11,600 (US$ 353) per diver.
Best Time To Dive: Liveaboards mainly run between November and May.

Top Tips For Diving In Krabi

  • Always dive with a certified dive shop to make sure safety procedures are being upheld.
  • Those that might get anxious about spending time underwater can opt to go snorkelling instead. The shallow waters around the island coasts are teeming with marine life, just like Finding Nemo, but without the heavy equipment.
  • Make sure your travel insurance covers scuba diving.
  • Consider staying at a dive resort for a fully-immersive experience.
  • Always dive with a buddy, and make sure you do all the safety checks before getting in the water.
  • Remember that you shouldn’t fly up to 18 hours after diving, so make sure you book any flights plenty of time after your final dive.
  • Rainy season in Krabi is in September and October, and although dive operators still run during these months, the visibility can be a lot lower.