In whole Hawaii you have to pay only on the beach Hanauma Bay. This Bay is in southeast of O'ahu island. Main reason is effort to save nature. Unfortunately huge number of visitors had a bad impact on corals which are almost dead now. The beach is closed on tuesday. Plenty of fish and rich corals were famous. It was a perfect place to snorkeling. Visitors could feed fish so they were comming in a big numbers. That is not allowed any more. But even nowadays a million people visit this place every year.
Visitor has to watch 15 minutes long movie about the beach and coral's ecosystem. To get down to the beach you can take public transport. But from paid parking lot it is a short distance. Phone box, shower and refreshment that's all you can find on the beach.
Hanauma Bay is a volcanic crater it's one wall broke down and allowed to sea flood into it. Unfortunately corals are dead and thanks waves it is impossible to sea through muddy water. I was pleased by sea tortoise that I could see first time in my life. Except these tortoises this beach was far away behind beauty of beaches on Ko Adang in Thai national park Tarutao.