We went to Sian Ka'an in May 2010 and it was a great trip. We were picked up from our hotel in Cancun, and on the way to Tulum, our tour guide provided us with information about the tour and other things to do in the area. It was a bit of a drive however, and we were in a full 12 passenger van so it wasn't as comfortable as it could have been. Upon arrival at the location, we were shown to the facilities and brought out to the dock. I should mention that the facilities did not have running water at the time of our tour, so be sure to use the restroom when you stop along the way. Once in the kayaks it was an amazing trip. The scenery was beautiful and it was so peaceful. If doing this trip you and your partner should be in reasonable shape. We kayaked for a few hours and we could definitely feel it the next day. After this we had a snack of fresh fruits, then headed for a hike to a beautiful beach. It was a fairly short hike, and hiking shoes were definitely not a necessity. Following the trip to the beach we went to another location to go snorkeling in a cenote. This was definitely a cool experience. You snorkel through a cave, dodging stalactites and stalagmites, and see lots of interesting formations. There aren't many varieties of fish, so if your dream is to snorkel surrounded by dozens of colorful varieties of fish, this isn't your snorkeling trip. However it was a very cool experience. Finally we went to a local restaurant in Tulum for 'lunch' around 3:00pm. The food was quite simple but it was extremely good.