Fascinating Place - but use a different tour operator - The Sian Ka'an Biosphere Reserve is a fascinating place! However, getting there is not easy. The road from Tulum down along the coast towards Punta Allen is a dirt track, full of potholes, requiring slow travel speeds. So plan on a 2-hr ride to cover 10-12 miles. (We still think it is worth the lengthy travel.) We booked this particular tour because it was offered through a TripAdvisor, and assumed the tour operator would be of good quality. This was not the case. The tour operator was ½ hour late picking us up (originally scheduled at 5:50 am). The tour director slept in the front seat until we reached Playa del Carmen. The tour van stopped at a gas station, where we were told we should change into our swimsuits. We each paid 5 pesos to get access to a filthy stall in a dirty bathroom. Once we entered Sian Ka’an Biosphere, the tour director gave a short introduction to what our plan was for the day, in Spanish, intermixed with English – speaking very rapidly. Somewhere south of Zamach, we finally transferred into 3 boats that took us down the lagoon. We stopped at a place where there were a couple of porpoises periodically surfacing. We were able to observe them for a bit. We then traveled further down the lagoon to the barrier reef, where we were provided with snorkel and fins so that we could snorkel along the reef. However, this activity only lasted about 15-20 minutes. We gathered back in the boats and sped back up inside the reef to a sandy area beside a spit of land, where it was shallow enough that we could stand and swim in the water. Here we spent 40-45 minutes, before climbing back in the boats and traveling up the lagoon to a small village. (I did not catch its name.) We had a nice fish lunch here. We next learned that the second part of the tour (viewing manatees) would not happen because the guide for it was not available. (Again, the explanation from our guide was very brief.) We then circled around the island of birds (Isla Pájaros), which was very interesting. Such a profusion of different birds. Then it was back to the van, and the 2-hour ride back to Tulum. When our guide was asked about a kind of fish, his answer was, “It’s a fish. I don’t know.” Questions about flowers or birds yielded a similar response. The ride back out the dirt road was much rougher because the van was being driven faster. We were thrown hard against the insides several times. When we arrived in Tulum, I was surprised to see that the guide switch out of the driver’s seat and the original driver take over. Our trip down the dirt road was not as rough when the regular driver was driving. We will go back to Sian Ka’an in the future, but we will find a more reputable tour company with whom to travel.