Siaes Tunnel Dive Site

Site Overview

Siaes Tunnel, within the Ulong Island & Ulong Channel of Palau, is one of the region's most rewarding dive sites and a highlight of any Micronesian diving trip. A large vertical tunnel dropping past whip corals and sea fans to a wall opening where grey reef sharks cruise outside. Geographically the site features tunnel and wall formations built from rock and coral substrate, dropping from a shallow top of around 10 metres to a maximum depth of about 42 metres, with an average working depth near 25 metres. Visibility is typically excellent, ranging from 20 to 40 metres, while water temperatures hold between 27 and 30 degrees Celsius year-round. The marine life is the headline attraction. Divers routinely encounter Glassy Sweeper (Pempheris schomburgkii), Grey Reef Shark (Carcharhinus amblyrhynchos), Whip Coral Shrimp (Pontonides ankeri), Hawksbill Turtle (Eretmochelys imbricata), Bigeye (Priacanthus hamrur), alongside dense reef fish, invertebrates, and the soft and hard corals that blanket the reef. The mix of nutrient-rich currents and Palau's protected status makes Siaes Tunnel one of the most reliable places in the country to see both abundant macro life and large pelagic visitors on a single dive. Siaes Tunnel is best enjoyed as part of a boat programme out of Koror, and it rewards wide-angle photographers, naturalists, and adrenaline-seeking drift divers alike. The Palau Protected Areas Network helps keep the reef pristine, so divers are asked to maintain perfect buoyancy and respect the fragile coral at all times.