Maria was very responsive to my questions before arriving. They have high quality equipment and know what they are doing, which is very important. They made sure all the safety equipment (helmets and life vests fit properly before going out on the water). I recommend taking a light sweater/ rain jacket and putting it in the water tight container that goes with you in the raft since the weather changes so radically.
In addition, we would have enjoyed the trip more if our guide had spoken better English. His English was really minimal and that was a pity as we would have liked to have known more about the park and surrounding area.
I also highly recommend renting mountain bikes at the end of the rafting experience and riding back through the National Park to the starting point! Beautiful area!