I was the Assistant Cruise Director of the Elation for six months and just recently got off. Let me try and help you. Just pay the money and go to Chichen Itza. It's a long day, but it's worth it. Whatever you do, don't go on the Beach Break. You can go to the beach by yourself, and unless you drink like a fish there is no reason to pay them $35. You're paying for the alcohol. Kaying though the mangroves in okay but tough. It will definately test your strength. Honestly, I would go on one of the ruins tours, or just stay on the ship. The beach there is really dirty, and somewhere you want to be. Sorry for the bad new, but I think you would like Chichen Itza.