1St Cathedral

First Cathedral is a dramatic lava-tube cavern with two-story vaulted ceilings and collapsed skylights that beam sunlight onto a central altar rock. Divers enter through a broad arched opening into an open chamber and can swim through tunnels, side passages and smaller back chambers; an adjacent underwater pinnacle and steep lava-walled reef add to the volcanic topography. Marine life is abundant along the structure, commonly including turtles, reef sharks, lobsters, octopus and various reef fish. Dives are boat-only via a mooring on the adjacent pinnacle. Depths range from about 25 to 60 feet, with divers typically descending to the top of the cavern at 25-30 feet and the chamber floor near 60 feet. Visibility is generally very good, often around 80-100 feet, and water temperatures are warm, roughly 70-80°F. Conditions tend to be calm with minimal current but noticeable surge; a typical route goes from the mooring through the arched entrance into the sunlit chamber and out the narrow exit tunnel, timing the exit with surge so divers are flushed out. Notable hazards include strong surge through the narrow exit, stirred-up sand that can reduce visibility, and the site may be unsafe in rough sea or strong surf. The site is suitable for Open Water certified divers using standard recreational gear, and smaller groups are recommended for best conditions.