About Hanauma Bay

Hanauma (pronounced "ha-NOW-mah", in Hawaiian) is a marine embayment formed within a volcanic coneand located along the southeast coast of the Island of Oahu (just east of Honolulu) in the Hawaiian Islands.Hana means 'bay' and uma means 'curve,' rendering "Curved Bay." Though some call it "Hanauma Bay," this is a tautology: Hawaiians simply call this feature "Hanauma". Hanauma is one of the most popular tourist destinations on the Island and has suffered somewhat from overuse (at one time accommodating over three million visitors per year). In the 1950s, dynamite was used to clear portions of the reef to make room for telephone cables to be brought in underwater. Some of this can still be seen today, and this section of the bay is called "Cable Channel."

Hanauma is both a Nature Preserve and a Marine Life Conservation District (the first of several established in the State of Hawaii). Reflecting changes in attitude, its name has changed over time from Hanauma Bay Beach Park to Hanauma Bay Nature Preserve.Visitors are required by law to refrain from mistreating marine animals or from touching, walking, or otherwise having contact with coralheads, which appear much like large rocks on the ocean floor (here, mostly seaward of the shallow fringing reef off the beach). It is always recommended to avoid contacting coral or marine rocks as cuts to the skin can result and neglecting such wounds may bring medical problems.

Approximately 3.9 million years ago, the Waianae volcano created the island of O?ahu. About 2.5 million years ago, the Koolau volcano erupted on the ocean floor, and continued to grow in elevation until about 1.7 million years ago, when it went dormant. Most of the eastern or windward portion of Oahu are remnants of this volcano. Most of the familiar geographic landmarks of eastern Oahu were created by eruptions from Koolau from about 500,000 to 10,000 years ago. The eastern flank of the Koolau volcano including the caldera slid into the sea, leaving the Koolau mountain range that can be seen today on the windward side of the island.

The Hanauma Crater is a relic of the latest (and perhaps final) burst of volcanic activity to occur on Oahu. Tens of thousands of years ago, a series of volcanic vents opened along the southeast shoreline of Oahu. Unlike the gentle lava flows currently building the island of Hawaii, the late-stage eruptions on Oahu were violent explosions. The volcanic vents that formed Hanauma Crater opened on the sea floor. Upwelling magma vaporized the ocean water and steam explosions atomized the magma into fine ash. The explosions built cones of ash, which solidified into tuff. The eruptions shattered the sea floor—coral reef and basalt—and scattered pieces that are now embedded in the tuff. Wave erosion eventually cut through the low, southeast wall of the crater, forming the current bay. The humuhumunukunukuapua'a (Reef triggerfish) is the fish of Hawaii/Hanauma bay, many of those can be seen close to corals next to and in the keyhole.

Hanauma Bay was purchased from the Bernice Pauahi Bishop estate by the City and County of Honolulu, and subsequently opened for public use. It was initially a favorite fishing and picnic spot for residents who were willing to travel out to the bay. In the 1930s the road along Hanauma Bay's corner of Oahu was paved and a few other amenities provided that made it easier to visit the beach and reef. After closure during World War II the Bay area reopened and became even more visitor friendly after blasting in the reef for a transoceanic cable provided room for swimming. In 1967 it was set apart by the State division of Fish and Game as a Marine Protected Area, a term used generically to describe any marine area that had some or all of its resources protected. In Hanauma Bay's case everything became protected, from the fish to the reef, to the sand itself. A volunteer group set up a booth at the beach and began teaching visitors about conservation of the reef and fish who lived there. More changes in the 1970s by the City cleared more area in the reef for swimming, made an additional parking lot, and shipped in white sand from the North Shore, leaving Hanauma Bay increasingly more attractive to visitors.

By 1990 overuse of the beach and surrounding area was a real problem, with visitors walking on the reef, swarming the surrounding areas, parking on the grass and on the sides of the road. Measures were taken to limit use and so visitor access was limited to the parking lot, and when it was full everyone after was turned away. A few years later in 1998 an admission fee was charged, further reducing the number of visitors. Then in August 2002 the Marine Education Center was opened at the entrance to the bay, where still today new visitors must watch a short film and receive instruction about conservation of the Bay's resources. Today Hanauma Bay sees an average of 3000 visitors a day, or around a million visitors a year. The majority are tourists.

 Toilet Bowl: Along the left point is the infamous Toilet Bowl, a natural spa tub that gently rises and falls with the tide. On days with high surf it is not gentle and can injure or kill people. The Toilet Bowl has been closed to the public since the mid 1990s.