Portlock - Hanauma Wall & Sea Cave, SE O'ahu

Accessible during rare days without wind or swell, this mile-long cliff of layered volcanic tuff is an excellent drift/wall dive to about 130 feet.  Visibility can exceed 100 feet during high tide while an outgoing tide sends a plume of murky water from Koko Marina east toward Sandy Beach.  Since this is the deepest water near shore encounters with rare or pelagic creatures is always a possibility.  The best marine life is found on a shelf strewn with car-sized rocks from 40 to 60 feet.  Waves reflecting off the cliff face creates very choppy surface conditions even during the best weather so caution is advised.  

The Sea Cave is a natural amphitheatre carved by waves & weathering.  Waves slamming into the cavern create strong surge, loud noise, and reduce illumination.  If the waves are big stay below 30 feet and be prepared to brace yourself.  Enter the chamber by swimming under a broad arch at 50 feet, formed when a huge portion of the cliff face broke away and slid beneath the surface.

A nearby cave leads vertically into a large sea-level chamber the size of a garage.  Only advanced divers with cave training & equipment should venture beyond the sunlit zone.  

 

 

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