Boat Cave

Meet the site

Boat Cave is exactly what the name says: a sea cave in the north-west cliffs big enough for a small boat to shelter in, and the operators sometimes moor the dive boat inside it. Extra Divers describe it as equal parts reef and adventure, with a depth range of 4–16 m and a torchlit finale in the cave.

The cave has an above-water section extending back into the cliff, and a floor at about 8–10 m that is completely covered in plate corals, angled towards the entrance to catch the light (Diveplanit, Divernet). The walls and ceiling carry red, pink and yellow whip corals and other colourful invertebrates, which come alive in torchlight. It is shallow and roomy enough that most divers feel comfortable, and the light from the entrance is always visible.

Outside, the reef along the base of the cliff has healthy hard corals and plenty of reef fish, and the blue beyond brings pelagics: Extra Divers mention wahoo and turtles, and the north-west corner of the island is known for passing sharks, dolphins and, in the wet season, whale sharks. Most dives spend the first part on the reef and finish in the cave.

Boat Cave is an easy introduction to Christmas Island's sea caves, suited to divers with basic buoyancy skills who want a taste of the island's karst without committing to Thundercliff or Thunderdome. It is on the more exposed north-west part of the coast, near Perpendicular Wall, and needs calm conditions. Photographers enjoy the plate-coral floor framed by the cave mouth.

What you might see

Plate corals, red, pink and yellow whip corals, wahoo, turtles, reef fish, reef sharks, spinner dolphins, whale sharks (seasonal)

Location

A sea cave on the north-west coast large enough for a small boat to shelter in, with a plate-coral floor at 8–10 m; reef outside.

Facilities nearby

Departs Flying Fish Cove jetty/ramp.