Cathedrals

Cathedrals is a lava tube dive site located just behind the fire department on Oahu, Hawaii, within a marine sanctuary. The site runs from 25 to 60 feet (8–18 m), with the cave bottom reaching a maximum of 18 m. The defining feature is a large lava tube fitted with natural skylights that cast shifting beams of light through the overhead rock — the effect that gives the site its name.

Being inside the marine sanctuary, the site supports a range of marine life including moray eels, nudibranchs, frogfish, spiny lobsters, whitetip reef sharks, and nocturnal invertebrates.

The cave environment and depth make this an advanced dive, and divers should be fully comfortable in the water before entering. As with all sites in the area, conditions on the day determine whether the site is accessible.