intermediate
    (54)

    Koh Haa Chimney – Krabi – Ao Nang & Koh Lanta Dive Site

    18m Max
    10-30m Vis
    boat

    Site Overview

    Koh Haa Chimney is one of Krabi – Ao Nang & Koh Lanta's most rewarding dive sites, offering exciting vertical cavern swim-through at 10 to 18 metres inside the Koh Haa Chimney formation requiring good buoyancy control and offering dramatic light effects and unique geological features. The site's healthy marine ecosystem supports diverse fish populations and vibrant coral formations throughout the diving season, creating an underwater landscape that rewards repeated exploration by both new and experienced divers alike. With warm water temperatures and exceptional visibility depending on conditions and season, Koh Haa Chimney provides excellent conditions for underwater exploration across all certification levels throughout the year. The site's diverse topography creates multiple habitat zones supporting different species at various depths, from shallow coral gardens teeming with juvenile fish to deeper sections where larger species patrol the structure looking for prey. Thailand's strategic position in the tropical Indo-Pacific ensures rich species diversity with both reef-dwelling and pelagic influences contributing to the vibrant marine communities found at this location. Nutrient-rich waters sustain abundant filter-feeding invertebrates including gorgonian sea fans, barrel sponges, and colorful soft corals that add spectacular color and texture to the underwater scenery. Whether searching for rare macro critters among the reef bommies or observing larger pelagic visitors cruising past the formation, Koh Haa Chimney consistently delivers memorable and rewarding underwater experiences for all who dive here.

    Dive Briefing

    "Begin the dive at the shallowest point of Koh Haa Chimney and take a moment to orient yourself before descending along the vertical cavern chimney. Maintain excellent buoyancy throughout the dive to protect the fragile coral formations and diverse marine life inhabiting the reef structure. Swim along the formation exploring the various depth zones while observing the diverse habitats and marine species that occupy each zone. Check overhangs, ledges, and crevices for resting moray eels, lionfish, and cryptic critters that shelter from the current. Pay special attention to the coral bommies, sandy patches, and reef edges where smaller species like seahorses, frogfish, and nudibranchs can be found with careful observation. Monitor your depth and remaining NDL carefully throughout the dive and maintain conservative ascent profiles. Keep your dive buddy in visual contact and communicate regularly using standard hand signals. Complete your safety stop at 5 meters deploying your DSMB before surfacing."

    Signature Marine Life

    cavern-dwelling species

    high

    Best: November, December, January

    lionfish

    high

    Best: November, December, January

    diverse reef fish

    high

    Best: November, December, January

    tropical marine species

    high

    Best: November, December, January

    coral invertebrates

    high

    Best: November, December, January

    Safety & Hazards

    • Cavern environment hazards including overhead obstructions, limited direct ascent, and reduced light conditions
    • Silt disturbance from fin kicks reducing visibility requiring careful finning techniques and torch use
    • Limited exit points in cavern sections requiring good buoyancy control and spatial awareness
    • Marine life hazards including lionfish and moray eels in dark cavern environments
    • Boat traffic requiring surface marker buoy deployment during ascent from cavern dive sites
    Nearest Chamber
    Vachira Phuket Hospital Hyperbaric Chamber
    80km away

    Traveler Notes

    Who is this for?

    Koh Haa Chimney is suitable for Advanced Open Water divers, offering rewarding encounters with diverse marine life in Thailand's productive waters. Underwater photographers will find excellent opportunities with the diverse topography and abundant subjects, from nudibranchs and frogfish to schooling pelagics and colourful soft corals. The site rewards both wide-angle and macro photography approaches depending on the conditions and subjects encountered. Divers with an interest in marine biology will appreciate the biodiversity on display in Thailand's unique marine environment, while those seeking relaxing reef dives will find calm conditions and beautiful scenery.

    For Non-Divers

    Non-divers can enjoy beaches, night markets, cultural sites, and scenic viewpoints near the dive location.

    Quick Stats

    Difficultyintermediate
    CertificationAdvanced Open Water
    Currentmild
    Water Temp27-30°C
    Best TimeNovember - April

    Dive Logistics

    Operators
    • Local Dive Center
    Pricing Guide
    $70 - $150
    Per 2-tank boat dive

    Photography Info

    Recommended Gear
    60mm macro
    16-35mm

    Best for: macro, wide_angle

    Nearby Stay

    Dive Hotel

    Krabi – Ao Nang & Koh Lanta3km away

    Check Availability

    Budget Guesthouse

    Krabi – Ao Nang & Koh Lanta2km away

    Check Availability