If you've never done it, which I hadn't, you must. It's a lot safer now than it used to be...you're no longer dragged off a beach, but rather let off like a kite from the back of a boat. Once you're up there it's a serene, quiet experience like none other.
Allow yourself a couple of hours for the whole thing...for two of us we were out on the boat for nearly an hour, and you need to consider time to get down to the beach and any delays that may occur. I think the regular price was about $50/person, but we got discounted tickets for listening to a sales presentation.