Mpai Bay

Mpai Bay is a dive site located off the northwestern village of the same name on Koh Rong Samloem, Cambodia. Despite its advanced rating, the site's maximum depth of 10 metres places it in relatively shallow waters, with the difficulty stemming from variable current conditions and occasionally reduced visibility rather than depth-related challenges. The bay opens to the northwest, exposing it to currents that sweep along the channel between Koh Rong and Koh Rong Samloem. This positioning means that water conditions can shift quickly, requiring divers to be adaptable and comfortable with changing current directions during a single dive. The upside of this current exposure is significantly richer marine life compared to the more sheltered sites. The underwater landscape at Mpai Bay features a mix of coral reef and rocky substrate, with patches of seagrass meadows in the shallower sections near the village. These seagrass beds are ecologically important, supporting juvenile fish populations and occasionally attracting seahorses that cling to the grass blades with their prehensile tails. The transition from seagrass to coral reef happens gradually, with coral coverage increasing as the bottom deepens toward the 10-metre mark. The reef itself hosts a healthy community of hard corals, with massive Porites colonies forming the primary structure. Barrel sponges have established themselves on the reef, their dark interiors sometimes sheltering small crabs and shrimp. At night, Mpai Bay transforms into a productive night dive location, with decorator crabs, Spanish dancer nudibranchs, and hunting octopuses all making appearances. The proximity to the village and its associated fishing activities means that occasional debris may be encountered on the seabed, but conservation efforts by local dive operators have improved conditions significantly in recent years. Mpai Bay is best experienced as a morning dive when currents tend to be lighter, offering a window of calmer conditions before the tidal flow strengthens.