Dilumacad Island (Helicopter Island)

One of El Nido's most-visited sites, combining two profiles in one dive. A gently sloping open reef (5–25 m) with strong coral coverage and resident green turtles is beginner- and Discover-Scuba-friendly, split by a sandy macro patch hiding frogfish and jawfish. On the seaward side, a natural limestone tunnel (~35 m long, entrance at 12–15 m) cuts through the rock and exits on the far side of the reef — a dramatic overhead swim-through requiring Advanced Open Water certification, 30+ logged dives, and mandatory flashlights.