Twin Caves

Meet the site

The north coast of Lord Howe between North Head and Fishy Point is made of volcanic rock, and the sea has cut ocean caves into it. Pro Dive's description of this stretch mentions Twin Caves and a blowhole cave that 'penetrates in about 100 metres', with striking light effects in the cave systems. The area's overall depth range is given as 2–37 m.

Ocean caves like these are formed where the sea exploits weaknesses in the basalt, and they often connect to the surface through a blowhole, which lets light in and creates shafts and beams through the water. The walls are covered in encrusting corals and sponges, and caves at Lord Howe typically shelter crayfish, slipper lobsters and soldierfish. Outside the caves, Pro Dive notes large schools of kingfish and trevally along this coast.

The important thing to understand is the difference between the two features. Twin Caves are twin entrances best treated as a swim-through and cavern dive in daylight. The blowhole cave that runs about 100 m into the island is a much more serious proposition: a long overhead environment in which surge from the blowhole can move divers around. Recreational divers should enter only as far as the guide leads and within sight of daylight.

The north coast is sheltered in southerly and south-easterly weather, and that is when the caves are dived; any northerly swell makes them dangerous. This is a site for Advanced divers with good buoyancy who are comfortable in overheads. Its current use by operators should be confirmed.

What you might see

Kingfish and trevally schools (outside), encrusting corals, sponges, crayfish, soldierfish

Location

Ocean caves in the volcanic cliffs of the north coast between North Head and Fishy Point, including a blowhole cave that runs about 100 m into the rock.

Facilities nearby

Departure from the Lagoon Road boatsheds.