Ream National Park tide times

Ream National Park covers approximately 210 square kilometres of coast, estuary, and marine habitat in Preah Sihanouk Province, Cambodia, bordering the Gulf of Thailand. The park was established in 1993 and protects a mosaic of mangrove forest, beach, open water, and coral reef that represents one of the most complete coastal ecosystem sequences remaining in Cambodia. The main terrestrial habitats — coastal forest and mangrove — are accessed via the Prek Tuk Sap estuary, a tidal river that bisects the park's interior.

The tidal regime at Ream is mixed semidiurnal, with a spring range of approximately 2 metres. The Gulf of Thailand coast has a predominantly diurnal character on some days — one high water dominates the daily cycle — which is characteristic of this semi-enclosed basin's tidal dynamics. The Prek Tuk Sap estuary is tidal for most of its accessible length, with the mangrove flooding cycle driven by the daily tidal signal. At high water, the mangrove root systems are submerged by 1 to 1.5 metres and the river appears to flow through a forest. At low water, the root architecture is fully exposed, and the mud between the roots is the feeding ground for the crabs, molluscs, and small fish that sustain the estuary's bird and dolphin community.

Irrawaddy dolphins (Orcaella brevirostris) are present in the Prek Tuk Sap estuary and the adjacent Gulf waters. This is one of the southernmost records of the species on Cambodia's coast; the Irrawaddy dolphin, also called the snubfin dolphin, is a small, round-headed cetacean with no prominent beak and a distinctive back-roll surface behaviour. Population estimates for the Ream coastal area are not well-documented; sightings are regular but not guaranteed on any given boat tour. The dolphins are most often seen at the estuary mouth and in the outer Gulf waters adjacent to the park, particularly on incoming tides when they follow fish into the estuary.

Boat tours of the Prek Tuk Sap from the park headquarters jetty last 2 to 3 hours and pass through the mangrove forest at a pace that allows observation of the avifauna — brown-winged kingfisher (a mangrove specialist found only in coastal Southeast Asia), mangrove whistler, black-naped oriole, and lesser adjutant stork (which nests in tall trees at the mangrove-forest edge). Sea eagles and ospreys hunt the estuary surface for fish. The tour's value is greatest at low water when the mangrove root community is exposed and most bird activity is concentrated at the water's edge.

Snorkelling at Ream is available at the park's beach (Koh Thmei island is offshore and has a small resort, accessible by park boat), with reef in 3 to 8 metres in acceptable condition by Cambodia standards — visibility is typically 3 to 6 metres and best on incoming tides. Fish diversity is moderate; the reef has had limited protection historically but recovery is measurable in the years since conservation enforcement improved.

The park headquarters is located 18 kilometres from Sihanoukville by road. Guided tours and boat hire are arranged at the headquarters. Independent entry is permitted to the beach areas; the estuary boat tours are guide-mandatory.

Predictions on this page come from Open-Meteo Marine, a gridded global ocean model. Accuracy is typically within plus or minus 45 minutes on timing and 0.2 to 0.3 metres on height — model-derived, not from a local gauge. The local tide authority is the Department of Hydrology and River Works, Ministry of Public Works and Transport, Cambodia.