Bull Sharks in Thailand: Where They Occur and How Safe It Is

Featured image (a bull shark outside Thailand, shown for illustration): Jerome Paillet (IFREMER, Laboratoire d'Océanographie Physique et Spatiale, Centr, CC BY 4.0, via Wikimedia Commons.

Are there bull sharks in Thailand? The short answer

Yes. Bull sharks (Carcharhinus leucas) occur in Andaman Sea coastal and estuarine waters, and some dive operators also place them in the Gulf of Thailand. Diver sightings are described as very rare. No operator can promise one. Treat a bull shark as a lucky bonus on a dive, not a target. Readers who want a reliable shark should jump to the final section.

Bull shark ID and behavior in brief

Bull sharks have a stocky build, a broad head and a short, blunt snout. The back is gray to light brown, and the underside is white. Females reach about 13 ft (4 m), while males top out near 12 ft (3.6 m), according to IFAW. Other sources quote smaller maximums, so "roughly 3 to 4 m" is a safe range. Their best-known trait is tolerance of fresh water. They enter estuaries and swim far up rivers. The IUCN Red List has classed the species as Vulnerable since 2020, with a decreasing population.

• Build: heavy, muscular, blunt snout
• Habitat: shallow coastal water, bays, estuaries, river mouths
• Size: roughly 3 to 4 m (10 to 13 ft)
• Status: Vulnerable on the IUCN Red List since 2020

Where bull sharks are mentioned in Thailand

Sources disagree on locations, and no single site is a confirmed hotspot. Dive guides name several places. Treat each row as a lead to put to a local operator, not a promise. Gulf-side talk centers on Koh Tao Sharks: Where, When and How to See Them. Andaman-side leads sit near Koh Lanta dive sites.

Can you realistically see one? Season, depth and odds

Odds are low. Sightings come at deep pinnacles and current-swept sites, where visibility and luck both matter. No season is confirmed for bull sharks. The October to May diving season often quoted for the Similan Islands applies to whale sharks and general diving, not to bull sharks. Ask the dive shop direct questions before paying.

• When was the last bull shark sighting at this site?
• How deep is the site, and what certification does it need?
• How strong is the current on this route?
• How large are the groups?
• What do you do if no sharks appear?

Shark attacks in Thailand: how dangerous are bull sharks?

Incidents are uncommon relative to beach visitor numbers. Published lists of bites from 2000 onward include a handful at Phuket and Phang Nga beaches, among them Karon, Kamala, Sai Noi and Nang Thong. Most involve foot, ankle or leg injuries in shallow water. Sources often say the species was "possibly" a bull shark, so attribution is unclear. Records are inconsistent across websites. Check the Florida Museum's International Shark Attack File for dated records. Bull sharks are the species most often suspected in shallow-water bites worldwide, because they favor warm, murky, coastal water. For beach context, see our Phuket shark safety page.

• Avoid river mouths and murky water.
• Skip swimming at dawn and dusk.
• Stay away from baitfish activity and fishing boats.
• Obey local flags and lifeguard advice.

Dive vs. snorkel vs. beach: who should do what

Divers and beachgoers face different risks. Diver encounters happen in open water at deep sites, where sharks are watched from a distance. Beach and estuary risk lies in shallow, turbid water near river mouths. Match your plan to your traveler type.

• Never bait or feed sharks.
• Never chase or corner a shark for a photo.
• Never swim at night or in murky water.

Cost, access and logistics trade-offs

Day trips from Lanta or Phuket keep boat time shorter and let you return to shore each night. Liveaboards and multi-day trips reach farther sites, with more diving but longer time at sea. Deeper pinnacles often need an advanced certification. Weather can close routes, and no operator can guarantee a bull shark. Compare current operator quotes rather than relying on any price you see in a blog.

Conservation and responsible behavior

Bull sharks face fishing pressure, habitat loss and climate change. Thailand protects reefs in marine parks such as Similan and Surin National Parks, and rules are published by the Department of National Parks. Thailand has also been described as banning shark finning, so read the official text. Responsible divers keep their distance and never touch or feed sharks.

Other sharks you are more likely to see

For a dependable encounter, look elsewhere. Our leopard shark guide covers resting sharks on sand. Blacktip and whitetip sharks are covered in the reef sharks page. For a bucket-list animal, read about whale shark season. Snorkelers can start with Phi Phi shark spots. For the whole picture, return to the Thailand shark hub.