Ulong and Siaes are a pair of diving areas within the Rock Islands of Palau, reached by day boat from Koror. The sites together cover an unusually broad range of diving styles, from the shallow Sand Bar reef suitable for beginners to the deep cavern system at Siaes Cave, which reaches sixty metres and is suited only to advanced divers with decompression awareness. Ulong Channel is the area's signature drift dive, a current-fed reef passage where strong flow is the defining condition. A reef hook is commonly used at current-driven sites to hold position and watch the marine life. Species across the area include whitetip reef sharks, Napoleon wrasse, giant morays, dogtooth tuna, bluefin trevally, and green sea turtles. Water temperatures are warm year-round, settling around thirty degrees through most of the year.
Monthly water temperature across Ulong & Siaes's sites, from satellite sea-surface data corrected for depth. The band shows the site-to-site spread.
Temperatures hold around twenty-eight to thirty degrees throughout the year, with the narrowest range occurring mid-year and slightly cooler minimums in the early months. The warm water makes a rash guard or thin wetsuit the practical choice for most divers. Currents vary significantly between sites and conditions can shift quickly, so divers should discuss current timing with operators before entering the water.
1 operator
Water temperature around Ulong & Siaes ranges from about 28°C in January to 30°C in May, based on satellite sea-temperature data for its dive sites.
With water around 28–30°C, a rash guard or 3mm shorty works in Ulong & Siaes year-round.
Fin maps 6 sites in Ulong & Siaes (6 scuba diving sites).
Across Ulong & Siaes's dive sites, January, February, March, April, November and December are most often reported as the best months to visit.
2 more sites to explore
