Hanauma Bay Nature Preserve: Being in such close proximity to Waikiki, Hanauma Beach is the most visited snorkel site on Oahu. The snorkeling inside this volcanic cinder cone is considered the absolute best. Hanauma Bay is open 6am to 6pm daily but closed on Tuesdays. It stays open for night snorkeling until 10pm on Saturdays and may be less crowded for at that time, although this activity is gaining in popularity.
Walk around the eastern side of Hanauma Beach to a place locally known as the “Toilet Bowl”. It is a 30-foot rounded hole at the end of a long ocean channel that was eroded out of lava rock by the continuous waves. As the waves come in the water level rises. This is the time to jump in. Then the water recedes until you are standing at the bottom. When the waves come back in they will float you right back up to the top. There is also a lava tube next to the bowl that runs under the lave shelf. If you can hold your breath for 30 seconds or so, you can let the current suck you into the tube and re-surface 30 – 40 feet away.
These days, this portion of Hanauma Bay may be closed. Hanauma Bay was a noted playground for Oahu’s ruling families. Hanauma Bay means “hand-wresting bay” because the Hawaiian men would play a game called “uma” where they would grasp each other’s hands forcefully until one would give in. Maybe an older version the game “mercy” we used to play as kids.