Koh Rong Samloem's diving is built almost entirely around reef sites, with the majority accessed by boat. The range runs from very shallow beginner reefs like Nudibranch Heaven and Lazy Beach Point through to the deep, advanced drift site at Lighthouse, which offers the deepest diving in the archipelago. Drift diving features at several sites, and Last Chance adds a wreck element. Nudibranchs, Jorunna Nudibranch and Blue Dragon among them, are a consistent draw, alongside Copperband Butterflyfish, Jenkins Ray and White Eyed Moray.
Monthly water temperature across Koh Rong Samloem's sites, from satellite sea-surface data corrected for depth. The band shows the site-to-site spread.
Water stays warm throughout the year, with the warmest conditions in the middle of the year and a slight dip toward the cooler end of the range in the early and late months. The best-months data points strongly to November through March as the prime window, with a secondary peak in May. April and the heart of the wet season see fewer recommended days, likely reflecting reduced visibility and less settled conditions.
9 operators
Sihanoukville, Cambodia
Sihanoukville, Cambodia
Sihanoukville, Cambodia
Sihanoukville, Cambodia
Sihanoukville, Cambodia
18 more sites to explore
Water temperature around Koh Rong Samloem ranges from about 29°C in January to 31°C in April, based on satellite sea-temperature data for its dive sites.
With water around 29–31°C, a rash guard or 3mm shorty works in Koh Rong Samloem year-round.
Fin maps 30 sites in Koh Rong Samloem (28 scuba diving sites and 4 snorkelling spots, with some suited to both).
The reefs here are well documented for nudibranchs, with Jorunna Nudibranch, Blue Dragon, Varicose Wart Slug and Giant Monkdragon all observed regularly. Copperband Butterflyfish, Eightband Butterflyfish, Bluestreak Cleaner Wrasse and Pink Skunk Clownfish are very common across sites. Larger animals including Jenkins Ray and White Eyed Moray are also frequently encountered, and Striped Eel Catfish can be spotted on shallower reef areas.
A good proportion of the dive sites are rated for beginners, including Nudibranch Heaven, Lazy Beach Point, Coral Garden, Corral and several others. These sites are shallow with mild conditions, making them well suited to those completing their first dives or building confidence. Intermediate and advanced sites such as Back Door and Lighthouse are also available for more experienced divers looking for drift diving or greater depth.
Almost all sites are reached by boat, which is the standard access method across the island. A small number of sites, including Sunset Beach Corner, also offer shore entry as an option. Several operators are based here, including Scuba Nation Diving Centre Cambodia, The Dive Shop, Bubbles Up Dive Center, Blue Lagoon Divers Cambodia and Cambodia Diving Group, all of which can arrange boat transfers.
The northern and mid-island sites, such as Back Door and Middle Tree, tend to be shallower reef and boulder formations suited to a range of skill levels. The southern tip concentrates the more demanding diving, with Lighthouse reaching the greatest depths and offering strong drift conditions, and Last Chance combining reef, drift and wreck topography. The shallow eastern sites like Coral Garden and Vietnamese Bay are calmer and more accessible for beginners.