David, we were there last week ( first time ever ) due to a port change brought on by the storms.
Costa Maya to me seemed to be a pretty new port. They had a very nice dock so no tendering and the shopping area was very nice.
Re/ Mayan tours, we had two to choose from. One was to Chacchoben, was approx. 4 hrs. Per the info I had, the site was approx a one hour ride, covered approx 10 acres and mostly un-excavated.
The other was to Kohunlich, was approx 7 hr. and involved a 2 hr. bus ride each way. Unfortunately there was road construction almost all the way which added to the travel time. The ruins were pretty well excavated and interesting, but if you have ever been to Chichen-Itza or Uxmal,these other Mayan sites pale in comparison.
I strongly urge you to take insect repellent--you will need it.
By the time you go, the road construction should be finished. Re/ heavy seas, as I said, there is a very nice dock there so there would not be any tendering involved.
I hope to go back there sometime as I think it was very pretty.
Hope I have helped . Happy Sails.