With just a day on Oahu in early August 2006, we dropped into Hanauma Bay for a snorkel. What a beautiful place! But the coral really is damaged and despite the educational efforts, people still walk on it. If you get to the outside of the reef in 15-25 feet of water there are some nice large coral formations and some good soft coral. There are turtles on the outside, too. On the plus side, the fish are unafraid everywhere, so you get some good up-close views of normally skittish ones like butterfly fish. The current can be a bit strong while trying to get back in. There are two major gaps to get out beyond the reef: one about mid-beach and the other to the extreme west. At high tide it is possible to go over the reef, but be careful not to touch.