Scuba Diving in Cambodia

Cambodia's coastline along the Gulf of Thailand is Southeast Asia's best-kept diving secret. While Thailand dominates the region's diving reputation, Cambodia offers a quieter, more intimate experience with consistently warm water, some pristine coral gardens, and a growing number of eco-conscious operators who take conservation seriously.

The diving is centered around the islands off Sihanoukville: Koh Rong, Koh Rong Samloem, and the more distant and dramatic Koh Tang. Depths range from snorkeling-friendly 3–5 metres to advanced walls at 30+ metres, making Cambodia accessible to both beginners and experienced divers.

Visibility is the main variable. During the dry season (November–May), conditions are excellent with 8–15 metre visibility and calm seas. The monsoon season (June–October) brings reduced visibility and rougher water, though some sheltered sites remain diveable. Serious divers generally plan around the dry season.

Cambodia's diving scene is also one of the more conservation-focused in the region. Organizations like EcoSea Dive conduct regular reef surveys, run marine conservation programs, and enforce strict no-touch, reef-safe policies. Choosing responsible operators here genuinely supports the health of Cambodia's marine ecosystem.

Visibility is the key variable for planning your Cambodia diving trip:

Cambodia's Gulf of Thailand supports a diverse marine ecosystem. Frequently sighted species include:

• Reef sharks: Blacktip and whitetip reef sharks are regular sightings at Koh Tang and outer sites; not aggressive and generally disinterested in divers
• Sea turtles: Green and hawksbill turtles; most reliable at Koh Thmei and Ream NP sites
• Seahorses: Koh Rong Samloem is outstanding for seahorse sightings; multiple species present
• Nudibranchs: Excellent variety and density; a macro photographer's delight throughout the year
• Cuttlefish: Common at most sites; fascinating behavior; can be observed for extended periods
• Barracuda: Often in schools at Koh Rong north shore and outer sites
• Lionfish: Present at most sites; beautiful but avoid contact (venomous spines)
• Moray eels: Particularly common at Koh Prins; several species
• Whale sharks (seasonal): Occasionally sighted April–May at deeper outer sites; not guaranteed but thrillingly possible
• Frogfish: For keen-eyed macro divers; Koh Rong Samloem is the best site

Choosing a reputable, safety-conscious operator is essential for a safe and responsible diving experience in Cambodia:

Cambodia is an excellent and affordable location to learn to dive or advance your certification. PADI courses available:

Liveaboard diving is the best way to access Cambodia's most remote sites — particularly Koh Tang and Koh Prins — which are too far for comfortable day trips from shore.

A typical Cambodia liveaboard trip:

• Duration: 2–3 days / 2 nights
• Price: $200–350 per person including all meals, accommodation on board, tanks, and weights
• Number of dives: 8–12 dives over 2–3 days
• Departure point: Sihanoukville or Koh Rong
• Operators: Scuba Nation runs the most established liveaboard program

Liveaboards are most worthwhile during peak season (January–April) when weather is stable and visibility is at its best. The overnight time on the water allows for night dives — an exceptional experience in Cambodia's warm, bioluminescent Gulf of Thailand.

For non-divers, snorkeling around Koh Rong and Koh Rong Samloem can be rewarding in calm conditions. The beaches on Koh Rong Samloem's Saracen Bay and Long Beach have reef patches accessible from shore in 1–3 metre depth, with reasonable coral coverage and small reef fish.

The full extent of Cambodia's marine life — particularly the reef shark sightings, larger marine animals, and deeper coral structures — is only accessible to divers. If you are interested in the underwater world but not yet certified, a Discover Scuba Diving program ($60–80) is the most rewarding investment and requires no prior experience.

Cambodia's reefs face threats from warming seas, coastal development, and illegal fishing. Divers can support conservation by:

• Choose eco-certified operators: EcoSea Dive and operators working with Marine Conservation Cambodia contribute reef monitoring data and conduct cleanups
• Don't touch coral: Even gentle contact damages coral polyps. Maintain good buoyancy control and keep fins clear of the reef
• Reef-safe sunscreen only: Standard chemical sunscreens are toxic to coral. Use zinc oxide-based reef-safe products or a rash guard
• Don't buy shell or coral souvenirs: The souvenir trade directly incentivizes reef damage
• Report illegal fishing: Cambodia's fisheries authorities and Marine Conservation Cambodia have hotlines for reporting illegal gill-netting and blast fishing

All major equipment (BCD, regulator, tanks, weights) is available for rent from dive operators. You can travel light and rent everything, or bring personal items for comfort:

• 3mm wetsuit: Water is warm (26–30°C) but a wetsuit is recommended for multiple-dive days and for sun/jellyfish protection; 3mm is ideal
• Mask and fins: Rental is available everywhere but personal mask fit is important for comfort; fins are less critical to own
• Computer: If you have your own dive computer, bring it; rental is available for a fee
• Underwater camera: Cambodia's macro life is excellent for photography; GoPro mounts and simple housings available for rent
• Reef-safe sunscreen: Essential; standard chemical sunscreen is banned by responsible operators
• PADI certification card: Required for all certified dives; bring physical card or have digital copy available
• Seasickness medication: Useful for the boat trip to more remote sites in any swell; take before departure