Dive Site: Koh Doc Mai

About Koh Doc Mai

Koh Doc Mai, meaning 'Flower Island,' is an uninhabited limestone island east of Phuket, renowned for its dramatic underwater topography and abundant marine life. It presents a stark contrast between its rugged, cliff-bound surface and the flourishing underwater walls, which are a kaleidoscope of soft corals, sponges, and anemones. This site is celebrated by macro enthusiasts for its incredible diversity of small creatures, making it a highlight for underwater photography. The island's diving is characterized by sheer vertical walls that plunge from the surface to depths exceeding 30 meters. The eastern side features two caves, one deeper requiring advanced training and a shallower, wider one accessible to comfortable divers. The western side offers a wall descending to a plateau, providing varied exploration opportunities. Currents can range from mild to strong, influencing dive plans and requiring consideration for diver experience. While larger pelagic species like barracuda, leopard sharks, and even occasional whale sharks can be sighted in the blue, Koh Doc Mai truly shines with its prolific macro life. Divers can spend an hour or more meticulously exploring cracks and crevices for unique critters. The water temperature remains consistently warm, typically between 28-30°C, and visibility generally ranges from 5 to 25 meters, with the best conditions from November to April. Diving here usually involves a drift along the wall, allowing divers to immerse themselves in the intricate ecosystem. The site is a popular day trip from Phuket and is often combined with other nearby famous dive sites. Its rich biodiversity and distinctive wall diving experience make Koh Doc Mai a must-visit for divers seeking detailed exploration rather than just large schools of fish.

Dive site facts: Koh Doc Mai

Depth

0–30 m

Typical dive

12–25 m, 50–60 min

Current

Moderate to strong

Visibility

5–25 m

Water temperature

28–30°C

Entry

Boat / drift

Level

Intermediate / Advanced

Dive type

Wall, cave, macro, drift

Region / port

Phuket, Andaman Sea

Coordinates

7.795, 98.508

Conditions & Currents

Currents at Koh Doc Mai are often moderate to strong, although they can vary depending on tidal conditions. They typically flow either north to south or vice versa, making it an excellent site for drift diving. Divers usually enter the water up-current and allow the flow to carry them along the wall, maximizing their exploration time with minimal effort. If currents are strong, staying close to the wall can offer some shelter and enhanced visibility for macro life. Due to the potential for strong currents and the wall's depth, good buoyancy control and current experience are beneficial for a safe and enjoyable dive. Visibility can also be variable, ranging from 5 to 25 meters, which can be influenced by plankton blooms during certain times.

Marine life & sighting chances

Nudibranchs

common

Moray eels

common

Pufferfish

common

Shrimps

common

Pipefish

occasional

Seahorses

occasional

Ornate Ghost Pipefish

occasional

Bamboo Sharks

occasional

Harlequin Shrimp

occasional

Leopard Sharks

rare

Blacktip Reef Sharks

rare

Whale Sharks

rare

Barracuda

occasional

Dive profile & how the dive runs

Diving at Koh Doc Mai typically begins with a boat drop up-current from your chosen side of the island, either east or west. The dive plan is primarily a drift along the sheer vertical wall, allowing the current to guide you. Divers descend along the wall, which offers an incredible display of macro life in its numerous cracks and crevices. On the eastern side, two notable caves can be explored; the shallower one towards the southern end is accessible to most divers comfortable in overhead environments, while a deeper, longer cave further north requires specific training. Throughout the dive, maintaining good buoyancy is crucial to avoid contact with the delicate coral and marine life covering the wall. Divers typically follow the wall's contour, gradually ascending towards shallower depths as air consumption dictates, eventually ending the dive at the opposite end of the island from the entry point. The safety stop is usually conducted in the open water near the wall, followed by surfacing for boat pick-up.

Underwater photography

Koh Doc Mai is a macro photographer's dream, offering an exceptional density of subjects. A macro lens (e.g., 60mm or 100mm) is highly recommended to capture the intricate details of nudibranchs, ghost pipefish, seahorses, and harlequin shrimp. Due to the wall's proximity, even with variable visibility, close-up shots are usually clear. Snoots can be particularly effective here to highlight small critters against the colorful background. Patience is key, as many subjects are well-camouflaged; take your time to scan crevices and overhangs. Good buoyancy control is paramount to avoid damaging the delicate coral and to maintain a stable position for crisp shots. While the site is known for macro, a wide-angle lens might be used for showcasing the dramatic wall topography or the large barrel sponges and sea fans, especially when visibility is good.

Combine with nearby dive sites

• King Cruiser Wreck

  Often combined in day trips from Phuket.

• Shark Point

  Known for leopard sharks and soft corals, frequently visited with Koh Doc Mai.

• Koh Phi Phi — Bida Nok

  Further south but a popular destination for liveaboards.

• Koh Phi Phi — Bida Nai

  Offers diverse marine life and typically calm conditions.

Getting there & logistics

Access to Koh Doc Mai is primarily via day trips from Phuket, usually departing from Chalong Bay. The boat journey takes approximately 90 minutes. These day trips often include 2-3 dives, frequently combining Koh Doc Mai with nearby sites like Shark Point and the King Cruiser Wreck. While possible to visit via liveaboard, it's more commonly part of a day trip itinerary given its proximity to Phuket. Phuket International Airport (HKT) serves as the main entry point, with numerous domestic and international flights. Accommodation options in Phuket range from budget to luxury, with Chalong, Rawai, Kata, and Karon areas being convenient for pier access. There are no specific park fees mentioned for Koh Doc Mai itself, as it's typically included in the overall dive trip cost.

Safety & environment

Safety at Koh Doc Mai requires attention to currents, which can range from mild to strong. Divers should possess good buoyancy control and be comfortable with drift diving techniques. The two caves on the eastern side should only be entered by divers with appropriate training and experience in overhead environments; the deeper cave is particularly restrictive. Nearest recompression chambers are located in Phuket, such as Bangkok Hospital Phuket. Evacuation from the site to a medical facility in Phuket would be by boat, followed by land transport. Divers should ensure they have comprehensive dive insurance that covers medical emergencies and evacuation. Always follow your dive guide's instructions, especially regarding entry points, dive profiles, and current management.

Who it suits — and who it doesn't

FAQ

Koh Doc Mai FAQ

Liveaboards diving Koh Doc Mai

These liveaboards may visit Koh Doc Mai on selected itineraries — the exact dive sites depend on departure, weather and conditions.

Mandarin Queen 9

Thailand

26 guests37.5 m

Manta Queen 8

Thailand

24 guests

$127/day

The Junk

Thailand

18 guests33 m

$163/day

Deep Andaman Queen

Thailand

23 guests30.5 m

$194/day

Explorer

Thailand

16 guests25 m

$150/day

Andaman

Thailand

20 guests26 m

$108/day

Stingray

Thailand

8 guests24 m

$245/day

Seatopia

Thailand

24 guests24 m