It is a great time- you sit on the deck of a catamaran ( i'm sure i butchered that spelling) enjoy the sun, have any drink you want-pretty much- served to you- and enjoy the incredible water. They do stop to snorkle if you like. When you get to Isla Mujeras you get lunch and more drinks. From there you can hang out on the beach or rent golf carts, shop or whatever. After a couple of hours on the island, you get back on the boat and cruise back to the resort. It is alot of fun and costs about $45-$55 a person if I remember right. It may have gone up, I'm not sure.