El Nido & Bacuit Bay · Philippines · Cave & cavern · Reef
Dilumacad Tunnel
A roughly 40 m tunnel lit by holes in its ceiling.
Area photo: Micluna · CC BY-SA 4.0
Bacuit Bay's swim-through set piece: a tunnel roughly 40 m long cut through Dilumacad, the island tourists know as Helicopter Island, lit along the way by holes in its ceiling. Around the island, seagrass draws feeding green turtles in summer and all seven of the bay's anemonefish species have been recorded.
Also known as Helicopter Island.
Where it is and how deep
11.1992° N, 119.3374° EApproximate position — the dashed circle shows where the site lies; your operator's briefing has the mooring.
The dive
The dive is built around the tunnel that runs through Dilumacad Island for roughly 40 m, with its entrance at 12 m on a site that works the 5–15 m band. It is an enclosed swim with a defined exit rather than a cave system, and holes in the ceiling let shafts of daylight into the passage, so you are never in full darkness — but the operators bill it for advanced divers only, and the exit is the crux: a narrower 10 m stretch that divers pass through one at a time.
Outside the tunnel the site is a normal Bacuit Bay reef dive around the island, and it rewards the time: in summer the seagrass draws green sea turtles in to feed, and all seven anemonefish species found in the bay have been spotted here. Current is typically low, under a knot, with visibility in the 10–30 m range.
Marine life and season
- Sea turtles
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Good | Good | Good | Good | Prime | Fair | Fair | Fair | Fair | Fair | Prime | Good |
Season follows El Nido & Bacuit Bay: May and November shoulder months bring the best visibility, often past 30 m; June–September typhoons can cancel boat days.
Know before you go
- The 40 m tunnel is an overhead environment and its exit narrows to a one-diver-at-a-time stretch: keep a guide ahead, settle buoyancy before entering, and stay off the bottom to protect visibility.
Sources
- Helicopter Island — scubago
- Dilumacad — wannadive.net
- Dilumacad Underwater Tunnel – Helicopter Island — Palawan Divers
- Palawan Divers – Discover El Nido Dive Sites — Palawan Divers
More dive sites in El Nido & Bacuit Bay
Wall
A vertical limestone wall falling from a 5 m coral garden to 35 m.
Cave & cavern
Boulders and rock formations cut with numerous swim-throughs.
Sand slope
Six metres deep, sandy and pool-calm — the bay's training ground.
Reef
A coral "underwater forest" sloping away from a 5 m garden.
Reef
Lettuce-coral gardens and a large colony of blue eels at 13–21 m.
Stingrays on the sand earn it the nickname "The Stingray Airport".
Similar dives elsewhere
A half-drowned cavern where two currents meet
A 30 m swim-through tunnel at 10 m with sharks resting inside
A collapsed reef cavern with easy galleries at 3 to 17 m
A tunnel in at 8 metres, out at 18