Hanauma Bay Marine Reserve – Hawaii – Oahu

Site Overview

Hanauma Bay is a protected marine life conservation area within a volcanic crater on Oahu's southeast coast, offering some of Hawaii's most accessible reef diving and snorkeling. The shallow bay features healthy coral gardens with extraordinary fish density including parrotfish, surgeonfish, and the state fish humuhumunukunukuapuaa. Green sea turtles are resident and frequently encountered at close range while the volcanic crater walls create a dramatic underwater backdrop. The bay is primarily a snorkeling destination due to shallow depths but certified divers can explore the outer reef areas where larger fish and occasional dolphins visit. The conservation status has preserved exceptional coral health and fish abundance making it an essential stop for any underwater enthusiast visiting Oahu. The conservation program established in 1967 has transformed Hanauma Bay from a degraded fishing area into one of Hawaii's most productive marine ecosystems with over 400 fish species documented within the bay. The volcanic crater formation creates a natural barrier protecting the reef from strong ocean currents while the shallow depths allow abundant sunlight to support healthy coral growth. Endemic Hawaiian species including the humuhumunukunukuapuaa thrive in the protected waters alongside visiting green sea turtles that have become remarkably habituated to snorkelers and divers.