Ngerikuul (The Tunnel) Dive Site
Site Overview
Ngerikuul (The Tunnel), within the Other Notable Sites (Macro & Special) of Palau, is one of the region's most rewarding dive sites and a highlight of any Micronesian diving trip. A photogenic swim-through cave holding glassfish, nudibranchs, and lobsters, good for wide-angle and critters. Geographically the site features tunnel and cave formations built from rock and coral substrate, dropping from a shallow top of around 8 metres to a maximum depth of about 25 metres, with an average working depth near 16 metres. Visibility is typically excellent, ranging from 10 to 28 metres, while water temperatures hold between 27 and 30 degrees Celsius year-round. The marine life is the headline attraction. Divers routinely encounter Glassfish (Parapriacanthus ransonneti), Nudibranch (Chromodoris), Lobster (Panulirus), Moray Eel (Gymnothorax javanicus), 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 Ngerikuul (The Tunnel) one of the most reliable places in the country to see both abundant macro life and large pelagic visitors on a single dive. Ngerikuul (The 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.
Dive Briefing
"Your dive at Ngerikuul (The Tunnel) begins with a controlled descent along the mooring line or wall, depending on the current on the day. You enter the tunnel and swim through, watching the glassfish clouds and the lobsters tucked into the walls. Plan to spend the deepest portion of the dive along the tunnel between 8 and 16 metres, where the rock is most colourful and the larger fish congregate. Keep your torch ready, deploy your DSMB at the exit, and avoid kicking silt on the floor. Mid-water, watch the blue beyond the wall for passing Glassfish (Parapriacanthus ransonneti) and other pelagics, and keep an eye on your no-decompression limits given the depths involved. Ascend slowly with a safety stop at five metres to off-gas safely. Because Ngerikuul (The Tunnel) can experience mild currents and occasionally reduced visibility after heavy rain, dive with a surface marker buoy and always follow your operator's site-specific briefing and emergency plan."
Signature Marine Life
Glassfish (Parapriacanthus ransonneti)
Best: Year-round
Nudibranch (Chromodoris)
Best: Year-round
Lobster (Panulirus)
Best: Year-round
Moray Eel (Gymnothorax javanicus)
Best: Year-round
Bigeye (Priacanthus hamrur)
Best: Year-round
Safety & Hazards
- Dark interior requiring a torch
- Depth to 25 metres
- Silt out if the floor is disturbed
- Sharp rock edges in the tunnel
- Minor current at the entrance
- Sun exposure on the surface
Traveler Notes
Who is this for?
Ngerikuul (The Tunnel) is aimed at intermediate divers holding at least a Open Water certification, and it suits those comfortable managing mild currents and maintaining neutral buoyancy along vertical terrain. Photographers, marine-life enthusiasts, and experienced drift divers will find it especially rewarding, while buoyant divers and photographers will enjoy it, while claustrophobic divers may skip. Divers who prefer calm, shallow, zero-current conditions should choose one of Palau's sheltered lagoons or house reefs instead, and anyone without the recommended certification should complete a check-out dive with a local operator first.
For Non-Divers
Non-divers can snorkel the cave mouth where light reveals the glassfish and corals.
Quick Stats
Dive Logistics
- Sam's Tours
- Fish 'n Fins
Photography Info
Best for: wide_angle, macro
Nearby Stay
Palau Pacific Resort
Arakabesan, Koror • 8km away
West Plaza by the Sea
Koror • 9km away