We went to Pigeon Island through one of the guys on the beach next to our guest house - we paid 7000 for the two of us to go - this included the national park fees (which I think was more than 4000), some water and coke in a cooler and some indian snacks and fruit. We could choose our own departure times. We went at 8am on a weekend - definitely go this early if you can - we were one of the first on the island but later it got crazy busy with sunbathers(???) and families just swimming. We had our own snorkeling gear and the fish were fantastic - saw an eel almost as soon as I got in the water. Really stunning. We came back at 11am but if we'd realized in advance how good it would be, we would have taken books and more food and made more of a day of it. A must do!