Thanks for your advice on Tulum.
We are back from the Independence of the Seas and we did not do any ruins. We were lazy. We did not want to spend the entire day trekking here there and everywhere. We were ambitious in our plans prior to the cruise and when we actually arrived to book the tours, well, It was fun to watch everyone leave and have the ship to ourselves. At Xmas when we cruised we rushed here there and everywhere and consensus was to simply just chill on this past cruise. People who I spoke to who went to Tulum said it was a long day and were glad they saw Tulum - beautiful by the sea but had little time left in Cozumel. I did get off for a short bit though to purchase some amethyst. Great prices in Cozumel for semi precious stones.