Going to Cancun over Thanksgiving - Are there any fun day trips?

ruins are good chichen itza is must tour, after this year you wont be able to walk up it, plus make sure you get the tour where you go to undergound pond to swim and lunch before going too chichen itza, also pirate cruise dinner is a must 2 pirates ships serve dinner ( steak or lobster or both) they battle after dinner, you like to get buzzed all you can drink omg i had best time there even with 2 kids with us, we stayed at smaller hotel this time over xmas will never stay at big hotels again cause they offered fishing 1/2 a day less then 150 each which is totally cheap ,by they keep fish( they dont keep well on plane) or 400 you keep fish

i went to that exact Marriott too(i work at one so it was a lot cheaper) and it is so incredible. there is no need for you to rent a car. there are buses running through out the night so you'd be saving soo sooo soooo much money by riding the bus! there is a jet skiing place across the street and you get to ride thru the canals. and you should definitely ride the ski scraper thing(cant remember what it's called but it takes you straight up and turns so you can have a spectacular aerial view) and if you are into the club scene, you have to go to senor frogs. that is such a fun club. i really hope you have as much fun as i did, but i did go there 3 years back when i was in high school. just remember not to rent any motor vehicles(a lot of them scam tourists into thinking they broke their vehicle and they will make you pay!) and DO NOT buy any sort of illegal drugs, they will lock you up so quickly, you didn't know what hit you.

The recommendations you have received above my answer are exactly what I was going to recommend. I just have to say you HAVE to go to Chichen itza, it is incredible!! make sure you take good comfortable tennis shoes because you will walk a lot. Being in Cancun and not going to Chichen Itza is like going to Cairo and not visiting the Pyramids in Giza. Have fun!