Hi Jeni, my name is Nacho and I am a tour guide here in Belize. I have heard a lot of people complaining of the long trip to Tulum. To get to Xunantunich is only about two hours and you spend about 1 1/2hrs at the site then on the way back usually you would have lunch for another 45 minutes then journey back to Belize City, which takes approx. another 2 hrs. but you get to past thru a lot of the creole settlements along the way that moved away from the city because of hurricanes. Also you get to see a lot of the country side of Belilze.
Well I hope this information was helpful, but if you need more info feel free to contact me at firstname.lastname@example.org