Along with Pearl Harbor, Hanauma Bay is probably the most popular destination for tourists visiting O'ahu. It was declared a protected marine area and underwater park in 1967, and over 400 species of fish have been cataloged within the bay. Known for the honu, or green sea turtle, these docile sea creatures nest in the faraway French Frigate Shoals and make their way to the Hawaiian Islands. The crater that Hanauma Bay sits in was formed 32,000 years ago, according to scientists, and it creates a perfect bay for people and the sea life to interact safely.
Most of the snorkeling and diving around O'ahu is lackluster when compared to hotspots such as Belize or Australia. This bay, however, is the best Hawai'i has to offer because of the high concentration of fish here. You can find large schools of fish scattered throughout different places but not so many in one place at one time. Potential underwater sightings at Hanauma Bay could include juvenile jack trevally (papio), octopus (tako), the famous state fish called the humuhumunukunukuapua'a and its various trigger-fish buddies, eels of all types, goat fish (weke), bone fish (o'io), needle and stickfish, a ton of parrot fish (koʻolauloa iʻa), and countless others.
There are lifeguards on duty and stores to buy anything you would need to enjoy this beach. First-time visitors need to watch a short video on the conservation and safety rules before entering the water. About 3,000 visitors per day visit the park, nearly 1,000,000 each year. The park is closed on Tuesdays to give it a break from the heavy traffic. There are shuttles to and from Waikīkī and a $7 entry fee. Kids under 12 years old are free, and so are all active military and locals with state IDs. The parking lot fills up quickly, so show up early.