Authentic - We booked through our resort. The boat, deck hands, drinks and lunch were wonderful! The current is very strong so I wasn't able to snorkel or swim at the drop offs. I am not a strong swimmer. You are dropped off a good distance from the reef and have to swim over. The boat then comes over to pick you up so you don't have to swim back to it. The island is very crowded and there isn't much room in the water as it is roped off a couple hundred feet from shore. It is very hot so be prepared. Lots of walking. There are tons of souvenir shops, restaurants and food carts of all kinds. They are on island time so make sure you aren't sitting down to eat 20 min before the boat is due back to get you. You can rent a golf cart to tour the island. I would recommend because you get 3 hours and there just isn't that much to do. We couldn't find any beach chairs to rent so you just carried your stuff and dropped it where ever to jump in the water. Items in the shops are cheaper than at the resort so bring plenty of cash for food, drinks and gifts. There is a free tequila tasting at the shop where the boat drops you off. That was nice. Everyone there will try the " I remember you. I am the bar tender at." Dont fall for it. They are trying to lure you into their shop or what ever they want to sell you. They see the bracelet you have on. They do not work at your resort.