Hanauma Bay is Hawaii's most famous snorkeling destination. The bay is in a well maintained state park that is open from 6am to 6pm except Tuesdays. One day per month the park stays open until 10pm for night time snorkeling. The park charges an entrance fee of $7.50 per person. The snorkeling at Hanauma Bay is good, but far from Hawaii's best. The water tends to be murky and can sometimes have high bacterial counts. The bay is always crowded at all hours of the day..